Objective To investigate the effect against exercise-indused fatigue in mice by aqueous extract of Ludisia dis-color and its mechanism .Methods Male mice were randomly divided into five groups including low ,middle ,high dose groups [aqueous extract of Ludisia discolor at dose of 1 .22 ,2 .44 ,4 .88 g/(kg · d) respectively ] ,positive control group [aqueous ex-tract of Rhodiola ,at dose of 2 .34 g/(kg · d)] and control group (distilled water ) .After intragastric administration for seven days ,mice were measured for loading swimming time ,and were tested 90 minutes after loading swimming for blood urea nitro-gen ,blood lactic acid and hepatic glycogen levels .Results The blood urea nitrogen was significantly decreased (P<0 .05) in aqueous extract of Ludisia discolor groups ,and hepatic glycogen was significantly increased (P<0 .05) in a dose-dependent manner .The blood lactic acid was significantly decreased in high dose group ,and weight loading swimming time was prolonged (P<0 .05) .The effects of Ludisia discolor is similar compared to Rhodiola .Conclusion The aqueous extract of Ludisia dis-color has anti-fatigue action in mice .The mechanism might be related with the increased glycogen reserves ,increased glucose aerobic decomposition ,as well as reduced anaerobic glucolysis and reduced protein breakdown .