Martin J. Brown, 54, a patent attorney who was a partner in the Washington law firm of Bernard and Brown where he had worked for the last 29 years, died Saturday at his mother's home in Little Rock, Ark., after a heart attack. He had been visiting relatives.

Mr. Brown was a native of Little Rock. He earned a bachelor's degree in chemical engineering at Purdue University in 1948 and was a 1951 honors graduate of George Washington University's law school. He served in the Merchant Marine during World War II.

He was an examiner with the U.S. Patent Office before entering private practice. Mr. Brown was an authority in patent law as it applies to the petroleum industry.

He was a member of the City Tavern Club and the Army and Navy Club. His professional memberships included the American and D.C. Bar Associations, and the International Patent and Trademark and United State Trademark associations.

Mr. Brown was a resident of Arlington where he had been a member of St. Andrew's Episcopal Church for the last 22 years. He had been an usher at the church.

Survivors include his wife, Pamela, of Arlington; a son, Martin Jr., of Los Angeles; two daughters, Tracey Arne Brown of New York City and Paige Brown of Arlington, and his mother, Delores Meyer, and sister, Jeanne Lancaster, both of Arkansas.

The family suggests that expressions of sympathy be in the form of contributions to the Martin J. Brown Memorial Fund at St. Andrew Episcopal Church in Arlington.