Abstract: The effects of chilling temperature on in vivo chlorophyll a fluorescence induction kinetic curves of tomato leaves from several varieties with different chilling-tolerance had been studied. The experimental results indicated that, after chilling treatments, chlorophyll a fluorescence induction kinetic curves of tomato leaves were changed obviously,the Fv/Fo and Rfd values were decreased,and the primary light energy conversion of photosystem II and the potential photosynthetic activity had been inhibited. Our results obtained both at seedling and blooming stages showed that, there were good relationships between the degree of changes of the fluorescence curves, the two fluorescence parameters of tomato leaves and the known order of chilling-tolerance of these tomato varieties. It is considered that, in vivo chlorophyll a fluorescence induction kinetics method is a sensitive, rapid and reliable tool for chilling-tolerance detection in tomato, and this method could be applied to chilling-tolerance detection in other green plants.