OBJECTIVES: China is far behind the international standard in health equity. The main purpose of this paper is to evaluate the equity of health services utilization of rural residents in western China and analyze its influencing factors, thus raising policy suggestions to improve the equity of health system. METHODS: Related data on health services utilization of rural residents were collected through random-sampling household surveys. Based on the standardized variable of Health Need, the parallel equity of rural residents’ health service utilization is assessed by calculating Concentration Index (CI) and mean-value and difference testing among residents of different income levels, while the vertical equity is evaluated by calculating Index of Dissimilarity (ID) among residents of different ages. Besides, Two-step Model is adapted to analyze its influencing factors. RESULTS: On outpatient service utilization, Standard CI of two-week outpatient visiting rate, two-week outpatient visiting times and outpatient expenditure are 0.1048, 0.1213 and 0.5178 respectively, while ID of the three indexes mentioned above are 0.054719, 0.056134 and 0.011823 respectively (P<0.05). On inpatient service utilization, Standard CI of annual hospitalization rate, annual hospitalization times, days of hospitalization, inpatient expenditure and its compensation level are 0.07914, 0.0543, -0.098, 0.3012 and 0.1740 respectively, while ID of the five indexes mentioned above are 0.053098, 0.06122, 0.308912, 0.316444 and 0.379235 respectively (P<0.05). Health status, financial ability, educational level and marital status have significant influence on health service utilization equity. CONCLUSIONS: Parallel inequity of health service utilization of rural residents of different income levels exits in outpatient expenditure, inpatient expenditure and its compensation level, while vertical inequity of rural residents of different ages exits in days of hospitalization, inpatient expenditure and its compensation level. Comprehensive measures should be considered to alleviate the inequity of health service utilization in rural residents who live alone, come from less well-off families and have poorer health, lower educational levels.