Low temperatures pose a critical limitation to the physiology and survival of chilling-sensitive plants. One example is the genus Paphiopedilum (Orchidaceae), which is mainly native to tropical and subtropical areas from Asia to the Pacific islands. However, little is known about the physiological mechanism(s) underlying its sensitivity to chilling temperature. We examined how chilling-light stress influences the activities of photosystem I (PSI) and photosystem II (PSII) in three species: P. armeniacum(杏黄兜兰 P. armeniacum), P. micranthum,(硬叶兜兰 P. micranthum ) and P. purpuratum(香港兜兰). All originate from different distribution zones that cover a range of temperatures.