Harry R. Hughes, governor of Maryland, and Wei Anming, mayor of Hefei, peered into a gray stone well, smooth with age after six centuries of use.

"The legend is, if a control official drinks the water of this well, he will get a severe headache," Wei said.

Hughes looked interested: "Can I take a gallon of that back with me?"

So did Maryland learn from China as an irrepressible delegation of state officials and businessmen led by Hughes invaded this landlocked, little-visited province of Anhui. It was an experiment in state-to-province relations that both sides applauded even if the stolid burghers of Anhui were not quite prepared for all the passions and folkways of their American guests. n

The Chinese had spared no detail for the eminent Gov. Hughes, even though he has only one tenth the number of constituents of his Anhui counterpart, Zhang Jingfu.

The Anhui-Maryland sister state idea had the all-important blessing of former Anhui governor Wan Li, now a vice premier, who enjoyed a gala tour of Maryland last year.

The week-long return visit by Hughes to Maryland's "sister" province was one of the highlights of the Hughes China trip. Hughes, his wife and 12 Maryland business and education leaders arrived in China on June 4, after a four-day stop in Tokyo, to establish a Far East bureau of the Maryland State Office of Economic and Community Development. Hughes left Anhui over the weekend and after a stop in Shanghai was due to arrive in Canton today. The delegation is scheduled to return to the United States on Sunday.

A few weeks before Hughes' arrival in Hefei, workers rushed to install a new decorative fountain near his guest house. Hughes, his wife Patricia and his daughter, Elizabeth, a summer clerk in the Baltimore law firm of Venable, Baetjer and Howard, enjoyed a suite of rooms once occupied by chairman Mao.

The bathroom had a hugh L-shaped tub, about six feet long on each side, and a chaise lounge, perhaps a resting place for Mao's lifeguard.

The delegation was welcomed at the airport by hundreds of school children waving flowers, doing synchronized dancing, beating drums and lighting firecrackers. Such gaudy displays are rare in the post-Mao era, and members of the Hughes group were so inspired that their entrepreneurial zeal soared.

During a long bus ride, state Agriculture Secratary Wayne A. Cawley Jr. gazed fondly at a beautiful little valley, so full of ripening rice that everything looked green as a new pea. "Two combines could harvest this from one end to the other in no time," he said. What of all the Chinese peasants put out of work? someone asked. "They could do something else, make fertilizer maybe."

George L. Bunting Jr., president of the company that makes Noxzema products, perked up: "They'd have more leisure time to buy more cosmetics." "More machinery, more oil," observed Henry Rosenberg, board chairman of Crown Central Petroleum, pausing in his daylong effort to capture the perfect picture of a rice paddy and a water buffalo.

In Peking, the delegation members had worked hard at a series of talks with Chinese officials. Charles W. Cole Jr., president of the First National Bank of Maryland, arranged the first correspondent relationship for a Maryland bank with the Bank of China. Others took first steps in the long process of technical exchanges but in Anhui they gave way to natural feelings of enthusiastic boosterism.

Rosenberg presented the startled officials of the East Is Red Commune hospital, and children at the group's airport greeting, with Baltimore Orioles caps and jerseys, each bearing the number of former Oriole great Brooks Robinson, who is now working for Crown Central. Cawley, ever mindful of Eastern Shore poultry interests, added a few "win with chicken" buttons, which drew puzzled looks from the Chinese even when translated.

University of Maryland President John Toll was going to bring some small model terrapins, until he learned that in China, the turtle is a symbol for a cuckold.

The group got to see China's most influential leader, Vice Premier Deng Xiaoping, before their flight to Anhui. Deng struggled to remember if he had met Hughes during his 1979 trip to the United States and launched a sally at American editorial writers.

"They also should be regarded as powerful people, since they control public opinion," Deng said, not seeming to be aware of how much the editorial support of the Baltimore Sun contributed to Hughes' upset victory in 1978. "We are very familiar with editorial writers in our country," Hughes said. "I'm not afraid of them," said Deng.

Deng, 75, had managed to climb the 3,000 feet of Anhui's beautiful Yellow Mountain last summer. When the Hughes party reached the moutain, however, only three of its 16 members plus three reporters decided to try.

Hughes said he stayed behind because his wife and daughter "were pretty scared." They had learned that several Peking-based ambassadors brought to the resort earlier this year had declined to ride along the narrow road to the beginning of the climb, much less try the thousands of steps up the mountain.

The dangers became clearer when the six returning climbers rode down the same road and smelled explosives. A half hour later three tremendous explosions brought Hughes and his state police escort, Cpl. James Lyons, dashing outside. It was just a road crew blasting, some of the nonclimbing delegation members assured them, and continued their poker game.

Hughes and his family had made a shorter climb, while the three climbers raced up Yellow Mountain. The winner was Fairchild Industries President John F. Dealy, 41, a racketball and tennis devotee. Not far behind were Toll, 56, and Noxzema chief Bunting, 39. At the mountaintop, Toll demanded more activity from the sometimes reluctant press. He woke up at 3:30 a.m. the next morning to be certain he saw the breathtaking sunrise, while less enthusiastic members of the party slumbered.

Toll and Chuan-Sheng Liu, acting director of the University of Maryland's Plasma Physics and Fusion Energy Studies Laboratory, arranged more exhanges with Chinese universities. Liu, whose family is from Anhui, served as Hughes' interpreter.

Toll was the catalyst for the Maryland-Anhui connection, through his friendship with Chinese-American Nobel laureate Chen-ning Yang, who knew Vice Premier Wan, the former Anhui governor. Others in the Hughes party included Economic and Community Development Secretary James O. Robertson, who continued discussions with the Chinese about sending one of their city experts to study at Columbia, and Dr. Richard S. Ross, dean of the Johns Hopkins medical faculty, who discussed more exchanges with China research institutes.

Eugene V. Allen, vice president of legal affairs for Black and Decker, heard the Chinese express serious interest in sets of the company's power tools. Bunting explored domestic sales to China, which now buys only for tourists and foreign resident use. Dealy discussed several proposals, including a suggestion that the Chinese build seats for Fairchild Aircraft.

Of all the tour participants, Agriculture Secretary Cawley perhaps made the greatest impression on the Chinese expecially net to the quiet, almost difficult Hughes. A banker and farmer, Cawley had entertained the Chinese on his Eastern Shore farm and even played bridge with Wan, who had purged during the cultural revolution allegedly for his overfondness for the game.

Cawley went to great lengths to drink his hosts under the table at the Anhui banquets, and showed everyone a special banner the Chinese made from the first wheat kernels harvested from seed he gave them last year. "Aw, Wayne, looks like a lot of crop to me," said Rosenberg.

Hughes was clearly enjoying an adventure far from the General Assembly, but sometimes memories intruded. At the China University of Science and Technology here, he gave a replica of the great seal of Maryland to University Vice President Yang Haibo, telling him, "it will give you great power."

"If it does, let me know," he added, "I've been trying to find some for a year and a half now."