B,Hb and Hct significantly increased in group B at t_2.3.PH increased in group B at t_1,furthermore exceeded the normal value,but gradually returned to the baseline at t_2;BE slightly increased at t_1 within the normal value;HCO~ - _3 unchanged before and after AHH.Lactic acid increased both in group A and group B at t_2.4.CaO_2、CcvO_2 decreased at t_1,but returned to the baseline at t_2 in group B;ERO_2 unchanged in group A,but slightly increased in group B after AHH.5.Na~+、K~+、BUN unchanged in both groups;Cl~ - decreased in group B at t_1,but returned to the baseline at t_2;Glu increased in both groups at t_2.Conclusion:The effect of rapid plasma Volume expansion with crystalloid or colloid on prevention of hypotension during induction of general anesthesia is similar.Vouven and Plasmalyte A were both safe and effective during induction of general anesthesia .Plasmalyte A was superior to stabilize physiological internal environment,while the effect of volume expansion and the time of maintainance of Voluven was superior to Plasmalyte A.