Rogers C. B. Morton, 64, a five-term congressman from Maryland's Eastern Shore, a former chairman of the Republican National Committee, and a cabinet officer under Presidents Nixon and Ford, died of cancer yesterday at Presquisle, his home near Easton, Md.

Mr. Morton was 6 feet 8 inches tall and he had a zest for politics to match his size. He was warm, gregarious and possessed of a down-home humor. He was well-connected in the Republican Party and in the world of business and he served the interests of his career. At the same time, he was a devoted outdoorsman and spoke frequently and forcefully in behalf of envoronmental causes.

A Kentucky patrician by birth, Mr. Morton was a gentleman former on the Wye River on the Eastern Shore by choice. He was elected to Congress from Maryland's 1st District, which is conservative in its politics and normally Democratic in its voting habits, in 1962. His constituents returned him to Congress for four additional terms. Many of the measures he supported on Capital Hill were designed to preserve the beauty of the Chesapeake Bay region.

They included laws to clean up pollution, the establishment of a National Park on the Assateague barrier islands, and the construction of a model of the Bay for the Army Cops of Engineers to study how the estuary works.His record on national environmental issues and on civil rights was regarded as mixed. He voted for the Civil Rights Act of 1964, but not for open-housing legislation in 1968.

In January 1971, Mr. Morton was sworn in as Secretary of the Interior. he replaced Walter J. Hickel of Alaska, who had been fired after challenging the Nixion White House on energy and conservation policy.

"I loved Interior," Mr. Morton said in a recent interview.

He had vowed on being nominated by President Nixon that he would "purify the environment." But he found himself increasingly isolated from the Nixon White House. When the Arab nations announced their oil embargo in October 1973, the oil and natural gas functions of the Interior Department were removed to the office of Emergency Preparedness. Mr. Morton announced that the controversial Alaska pipeline would have its southern terminus on the West Coast, but it was understood that the decision acutally had been made in the White House.

Mr. Morton watched with growing uneasiness as Nixon went down in the Watergate scandal.

In 1975, President Ford nominated Mr. Morton as Secretary of Commerce. In 1976, he became Mr. Ford's campaign manager for the GOP presidential nomination and in the closing days of the Ford Administration he served as a presidential counsellor with cabinet rank for economic and domestic policy matters. In fact, his duties in that post were widely regarded to be political.

Mr. Morton rose to the top of the GOP while in Congress. He was Nixon's floor-manager at the 1968 Republican National Convention which nominated Nixon for the presidency. He made the speech nominating Spiro T. Agnew, then the governor of Maryland, to be the candidate for vice president. In 1969, Nixon appointed him chairman of the Republican National Committee, a post he held until shortly before he went to the Interior Department.

Since 1977 Mr. Morton had lived on his farm at Presquisle. He has engaged in a boat-building business, having been an enthusiastic sailor most of his life.

"I used to get over here some part of every weekend, just to get away from that rat race in Washington," he said in a recent interview. "You never could get out of that rat-race as long as you were in Washington.

"Oh, you can't have been involved in Washington to the extent I was and not miss anything," he added. "I miss some of the associations. I had a tremendous lot of friends over there."

He added, "I tell people my iniitals C. B. stand for Chesapeake Bay. I'm relaxed, retired, having a good time building boats, trying to do well. I want nothing. That's my story."

In the same interview, Mr. Morton wondered whether he really had influenced events in the course of his long career.

His death drew tributes from both Democrats and Republicans.

Gov. Harry Hughes of Maryland, a Democrat, called Mr. Morton "a giant of a man both literally and figuratively. Though we were at one time political opponents, I considered him a friend and maintained the highest respect for his long and dedicated public service."

Sen. Charles Mathias (D-Md.) said Mr. Morton was "so human he made government itself seem human to people . . . Rog Morton really wanted to conserve the good things of America. He wanted to conserve the things that were threatened by the advances of modern life."

Bill Brock, the present chairman of the Republican National Committee, said Mr. Morton had been "loved and respected by all who were fortunate to know him . . . He brought to his government service a zest for life and a quality of personal integrity that enriched our nation."

George Bush, a former GOP chairman and an unannounced candidate for the Republican nomination for president, called Mr. Morton "a remarkable public servant who devoted his life to the best interests of the country . . . He was a friendly giant who felt as comfortable in the presence of presidents as he did with the working men and women of the Eastern Shore of Maryland . . . He will be missed by thousands of Republicans and Democrats who grew to admire and respect the decency and intergrity he brought to America's political process."

Rogers Clark Ballard Morton was born in Louisville, Ky., on Sept. 19, 1914. His parents were David C. Morton, a successful physician, and Mary Ballard Morton, an heiress to a flour milling business. One of his ancestors was Gen. George Orgers Clark, an officer in the American Revolution. He was one of three children. His older brother is Thruston B. Morton, a former U.S. senator from Kentucky.

Rog Morton was educated at the Woodberry Forest School near Orange, Va., and at Yale University, from which he graduated in 1937. Although he had a reading difficulty all of his life, he entered the College of Physicians and Surgeons at Columbia University. After a year, he abandoned plans to follow in his father's footsteps.

Mr. Morton served briefly in the Navy, but had to resign his commission because of a black ailment. He joined Ballard & ballard, the family flour business. In World War II, he enlisted in the Army as a private and rose to the rank of captain. He returned to Ballard & Ballard after the war and served as its president from 1947 to 1951.

In the latter year, the firm was merged with the Pillsbury Flour Co. Mr. Morton remained a director of Pillsbury and a member of its executive committee for several years.

By the time of the Pillsbury merger, Thruston Morton already was launched on his political career. Rogers Morton became heavily involved in his brother's campaigns and this was his baptism in politics. It was also the source of innumerable stories with which he would regale campaign with which he would regale campaign crowds throught his career.

One concerned efforts to win the vote in the mythical town of "Butterfly, Kentucky," and its surrounding county.The Morton brothers looked up the county leader, carried the area in the election, and then offered the postmastership of "Butterfly" to the man who had helped them. The man replied that he couldn't read, but his wife could, andwhy not offer the job to her?

The spectacular success of Thruston Morton was one of the reason Rogers Morton left Kentucky for the quiet of the Eastern Shore. "I love water and I love to farm," he said recently. And, he added, "I was sort of in his shadow out there."

He discovered the Wye River site while cruising the East Coast with his wife, the former Anne Jons, whom he married in 1939. He brought the property, rented more, and set up a 1,400-acre cattle-feeding operation. In recent years, he has sold off all the land except the 160 acres around his house.

In addition to their house on Wye River, the Mortons own a beach house in the Bahamas.

In addition to his wife, of the homes, Mr. Morton's survivors include two children, David C., of Brooklyn, and Anne McCance, of Alexandria, his brother, Thruston, and a sister, Jane M. Norton, both of Louisville, and one grandchild. CAPTION: Picture, Rogers C. B. Morton