Objective To evaluate the hemolysis and fatigue resistance self suspension ventricular assist device (NIVAD) in vitro.Methods Resettled NIVAD which is filled with 2 500 ml fresh anticoagulant blood from pig in vitro loop system.The speed of blood pump was adjusted to 8 000 rpm.The afterload and the flow of pump were set as 100 mmHg and 3.5 L/min respectively.Keep the temperature at around 37 degree centigrade which is equal to average internal temperature in pig.Then harvest and measure the free hemoglobin(FHB) of blood samples at different time points before and after working.Then calculated the normalized index of hemoylsis(NIH) by comparing to control group, the unused pig blood at the same period.In fatigue test, conditions remained unchanged, except the blood was replaced by pure water.The blood pump had operated for 90 d continuously and recorded its performance.Results The FHB of experimental blood is higher than that of the control.The normal index of hemolysis NIVAD is(0.0052 ±0.0019)mg/L.Fatigue test , the blood pump operated smoothly, and every parameters was stable.Conclusion The blood pump of NIVAD does a certain degree of destruction to blood, but the NIH is in criterion range of hemolysis, it has certain advantages compared to similar products in china and aboard.At the same time it has good resistance and stable property to fatigue.