SOME Hongkong graduates from the University of Sheffield in England said they would remain in the territory after 1997 to contribute towards its prosperity. More than 100 Hongkong graduates received their degrees at a congregation held recently at the Island Shangri-la Hotel. Ada Leung, a graduate from the Department of Law, said she would stay in the territory and put what she has learned at the university to practice. She said she had no plans to move and she had complete confidence in Hongkong. ''China's economic reforms have been quite successful and I believe Hongkong will benefit from China's open-door policy,'' Ada said. Philip Lam, a graduate from the Department of Engineering, said Hongkong would be a better place to develop his career since England was suffering from economic recession. ''There's no point to stay in England as the unemployment rate is high,'' he said. ''It's difficult to find a job.'' However, Philip was worried about the recent hostility between the British and Chinese Governments. ''I hope the British and Chinese Governments can soon resume their talks on the 1997 problem,'' he said. Despite his worries, Philip said he would not consider emigration in the near future as Hongkong is a better place to make money. Sir William Purves, chairman of Hongkong and Shanghai Banking Corporation, was conferred the honorary degree of Doctor of Law.