The dynamics of flowering and fruit set of five Cypripedium species was evaluated during 2003-2007 in Huanglong Nature Reserve, Sichuan. Examination of the breeding system suggests that flowers of Cypripedium are self-compatible but need pollen vectors for successful reproduction. No signifiacnt relations were detected between flowering time and fruit set in five Cypripedium species, which may be caused by that differnet Cypripedium species having different pollination systems. However, fruit sets depend negatively on the flowering duration in population level, which is relative to the learning ability of its pollinators in Cypripedium with typical deceptive pollination systems. In addition, fruit sets in 2004-2007 were significantly higher than those in 2003 in all Cypripedium species except C. henryi, thus pointing to the possibility that human disturbance had an effect on the level of fruit set because there were few visitors in 2003 due to SARS.