Objective To explore the application of auto-regressive integrated moving average (ARIMA) product season model in predicting number of inpatient and hospitalized expense of malignant tumor,and to provide scientific basis for hospital business management.Methods We collected inpatient data of malignant tumor from January 2007 to December 2015 in one hospital for model fitting,and used monthly data 2016 to verify the effect of model prediction.We predicted the number of inpatient and hospitalized expense of malignant tumor in 2017.Results ARIMA (0,1,1) (1,1,0) 12 was the best model for number of inpatient and hospitalized expense of malignant tumor,with prediction fitting errors of 1.1％ and 1.47 ％,respectively.The number of inpatient and hospitalized expense of malignant tumor in 2017 were predicted to be 7631 and 0.336 billion.Conclusion ARIMA product season model can better applied in the predicting of hospital business management.