Objective:By analyzing inpatient expense of appendicitis and its influencing factors in a grade A hospital in Hainan province, the paper aims to investigate the composition of inpatient expenses and the influencing factors, and thus offer reference for controlling excessive increase of inpatient expense. Methods: In the study, univariate and multivariate analysis were performed to analyze the influencing factors of inpatient expenses. Results: It was found that the percentage of visible service charge (including examination expenses and laboratory test expenses)was on the high side, while the percentage of invisible service charge(including operation expenses, nursing expenses and diagnostic expenses) was on the low side. Such four factors had significant effects on the impatient expense: the number of hospitalization days, age and gender of the patient, and whether the patient undergoes an operation or not. Conclusion: Medical service cost accounting should be strengthened,mscientific and rational pricing mechanism should be set up,the growth of visible service should be strictly controlled,and invisible service should be compensated to a greater degree.