Background: The Multidimensional Scale of Perceived Social Support (MSPSS) is one of the most widely used scales for social support. Although previous studies have shown good reliability and concurrent validity, conflicting evidence exists on its factor structures. Aim: To validate the MSPSS among caregivers of people with schizophrenia in China and assess its factor structure. Methods: A cross-sectional study was conducted of 449 family caregivers in 12 communities for psychometric testing, eg, internal consistency reliability, test–retest reliability, construct validity, exploratory factor analysis (EFA) and confirmatory factor analysis (CFA). Results: The MSPSS showed good internal consistency with a Cronbach’s alpha of 0.95, good test–retest reliability with intraclass correlation coefficient (ICC) of 0.91, and kappa ranging from 0.62 to 0.71. Concurrent validity was supported by its negative correlations with perceived stress, and significant positive correlations with caregiving rewarding feelings, family functioning, and coping. EFA yielded a two-factor structure (family vs non-family), while CFA generally supported a three-factor structure (family, friends, and significant others). Conclusion: Our findings show good psychometric properties of the MSPSS among caregivers of people with schizophrenia in China. EFA yields two-factor structure and CFA yields three factors consistent with the theory underlying the measure’s development.