THREE groups in Taiwan have for the first time held a public memorial event for the late chairman Mao Zedong, who led the communists to force the Kuomintang to flee the mainland in the 1940s. The Hong Kong China News Agency quoted reports in Taiwan as saying that the groups had organised a gathering at the weekend to remember the Great Helmsman. The memorial event was entitled ''Who is to judge on the achievement and mistakes in history?''. It said the groups had taken a stance of ''sympathy and respect''. Two of the groups are publishing houses and the third is an association of former political prisoners in Taiwan. In addition to a showing of a film entitled The Story of Mao Zedong, pictures, memorial badges, cassettes and T-shirts emblazoned with slogans of Mao's were on sale. A former political prisoner, Lin Shu-yang, who had been jailed for 32 years, said Mao should be recognised as a great man of history. He said Mao shattered the old systems adopted for thousands of years and created a new nation. His ideas had had an enormous impact on the people in the mainland, he said. A veteran unionist, Wang Li-sha, said he had sympathy and respect for Mao. ''Mao is a man of nationalism, patriotism, socialism and Marxism,'' he said. Mr Wang argued that the romanticism of Mao was that utopian thoughts could be put into practice. ''His persistence in the pursuit of ideals of mankind and its impact created will not vanish with the perishing of his physical body,'' he said.