Abstract: In order to select strong coldresistant tree species, seedlings of six tropical and subtropical species (Dillenia turbinata, Peltophorum tonkinense, Garcinia oblongifolia, Alstonia scholaris, Khaya senegalensis and Ormosia pinnata) were treated with the lasting times of 0.5, 3, 5 and 8 d at 10℃ respectively. The changes of physiological indices of these seedling were studied. The results showed that with low temperature stress time increasing, the relative electric conductivity of six seedlings tended to increase, the contents of free proline fluctuated rapidly, and the chlorophyll contents fluctuated slightly, whereas the contents of MDA generally increased and then decreased. Except for D.turbinata, the activities of SOD were closed to the controls after fluctuation. With increasing low temperature, the contents of soluble protein of six tree species were greater than or closed to the controls after fluctuation. Cold resistance of six seedlings was evaluated using principal component analysis and the their cold resistance was O.pinnata, K.senegalensis, A.scholaris, G.oblongifolia, P.tonkinense, D.turbinate.