Varied water parameters were studied with Pressure Volume technique at different root temperature in tomato, and the adaptation mechanism to the variation of root temperature was explored. The results showed that ψ s 100 ,ψ s 0,ROWC 0,b,ψ w 0 ,and ε of tomato leaf at lower root temperature(15～20℃)were higher than those at higher root temperature(30～40℃);while a , ψ s 100 -ψ s 0, -a-ψ w 0 were lower than those at higher root temperature, exception appeared to be very rare. Ac...