Sun Jun is Vice Chairman of both the Shanghai Society for Parasitology and the Shanghai Zoological Society. He has led projects funded by the National Natural Science Foundation of China, the 973 Program, and the Innovation Fund of Shanghai Municipal Education Commission. His research focuses on artemisinin's antimalarial action and resistance, the pathogenesis of Plasmodium, Babesia, Schistosoma and related control technologies. He has proposed three original theories: (1) hemozoin in schistosomes and malaria parasites is an iron/heme carrier rather than metabolic waste; (2) artemisinin kills parasites by blocking iron/heme utilization; (3) low iron/heme demand drives artemisinin resistance in Plasmodium.