Background: Providing equal treatment for those who have the same need for healthcare, regardless of their socioeconomic and cultural background, has become a shared goal among policymakers who strive to improve healthcare. This study aims to identify the socioeconomic status (SES) inequities in inpatient service utilization based on need among migrants by using a nationally representative study in China. Methods: The data used in this study was derived from the 2014 National Internal Migrant Population Dynamic Monitoring Survey collected by the National Health Commission of China. The sampling frame for this study was taken using the stratified multistage random sampling method. All provincial urban belt and key cities were stratified, and 119 strata were finally determined. We used logistic regression method and Blinder-Oaxaca decomposition and calculated the concentration index to measure inequities of SES in inpatient service utilization based on need. Sample weights provided in the survey were applied in all the analysis and all standard errors in this study were clustered at the strata level. Results: Of the total internal migrants, 18.75% unmet the inpatient service need. Results showed that inpatient service utilization concentrated among high-SES migrants (Concentration Index: 0.036, p <0.001) and the decomposition results suggested that about 44.16% of the total SES gap in inpatient service utilization could be attributed to the gradient effect. After adjusting for other confounding variables, those had high school degree and university degree were more likely to meet the inpatient services need, and the OR values were 1.48 (95% CI 1.07, 2.03, p =0.017) and 2.04 (95% CI 1.45, 2.88, p =0.001), respectively. The OR values for Quartile 3 and Quartile 4 income groups was 1.28 (95% CI 1.01, 1.62, p =0.044) and 1.37 (95% CI 1.02, 1.83, p =0.035), respectively. Conclusion: This study observed an inequity in inpatient service utilization where the utilization concentrates among high SES migrants. It is important for policy makers to be aware of them and more intervention should be conducted.