【Objective】To investigate the effect of pantoprazole on skeletal muscle wasting in cancer cachexia and the possible mechanism.【Methods】24 male BALB/c mice were randomly divided into control group（NN），cancer cachexia group（CC），pantrop? razole treatment group（PPI）. The mice in CC and PPI were inoculated subcutaneously with mouse colon adenocarcinoma C26 cells to establish a model of cancer cachexia. The mice in PPI group were gavaged with 75 mg/kg pantoprazole dissolving in physiological saline，while those in NN and CC group were gavaged with 0.1 mL/10 g physiological saline. The mice were killed 12d after treatment. The weight of gastrocnemius and tumour and the size of tumour were measured. The morphological change of skeletal muscle were evalu? ated by the method of stain with hematoxylin and eosin（H＆E）. The levels of IL-6 and TNF-α in serum were tested by ELISA. qRTPCR was used to assess the expression of mRNA of Myod1 and myf5 in skeletal muscle. The protein expressions of MuRF1，MAFBx， Myod1 and myf5 were measured by Western blot.【Results】Compared with CC group，pantoprazole can increase the weight of mice and gastrocnemius（39.8% and 24.2% ，respectively），cross section area（25.4%），levels of mRNA and protein of Myod1 and myf5（P < 0.05），while the levels of IL-6 and TNF-α decreased（30.7% and 18.9%，respectively），as well as the levels of protein ex? pression of MuRF1 and MAFBx（P < 0.05）.【Conclusion】Pantoprazole can attenuate the wasting of skeletal muscle，the potential mechanism may be related to the inhibition of inflammatory factors and UPS，and up-regulation of Myod1 and myf5.