Objective：To investigate the safe limit of warm ischemia time（WIT） for kidney graft after uncontrollable cardiac death（CD） in rat. Methods：Totally 140 SD rats were randomly divided into 7 groups according to the WIT（CD0，CD10，CD20，CD30，CD40，CD50，CD60 groups）. Each group had 20 rats，10 as donors and 10 as recipients. The left kidneys were harvested from the donor rats at 0，10，20，30，40，50，60 min after CD and the harvested left kidneys were transplanted into the left nephrectomized recipient rats whose right renal pedicles were ligated. The survival of recipient rats，recovery of renal function and degree of fibrosis were observed and checked. Results：Cold ischemic time was similar in all groups（P >0.05）. The survival rate，serum creatinine level and allograft fibrosis in CD10，CD20，CD30 groups were all equivalent to those of CD0 group（P >0.05） and the same results were acquired in CD40 group except that the serum creatinine level was higher than that of CD0 group（P<0.01）. All rats implanted with grafts for more than 40 min after CD（CD50 and CD60 groups） died within 7 d. Conclusions：WIT of the donor kidneys should be limited to less than 40 min for rat kidney graft from an uncontrollable CD donor；kidneys with WIT lasting for 30-40 min should be seriously considered for transplant.