Objective: To develop the Chinese primipara social capital scale (C-PSCS), and to evaluate its validity and reliability. Methods: The items of C-PSCS were developed based on Social Capital Scale by the World Bank and Social Network Scale. This scale was modified according to the characteristics of primiparas. We selected 10 experts who specialized in related field, and two rounds of seminars about content, cultural compatibility, primiparas' characteristics, and practicability. The finally C-PSCS included four dimensions: social trust, social reciprocity, social network, and social participation. Using purposive sampling to select 1 100 primiparas in their third trimesters (gestational weeks from 30 to 36 weeks). The validity analyses included content validity, construct validity and discriminant validity. The reliability analyses included Cronbach' α coefficient, and split-half reliability. Results: 1 035 questionnaires (94.09%) were qualified and the completion time was (13.23 ± 2.53) minutes. The total score of scale was 195.38 ± 45.98, and scores for social trust, social reciprocity, social network, and social participation were 30.26 ± 4.25, 22.84 ± 4.21, 34.23 ± 7.47, and 108.05 ± 41.96, respectively. The common factor cumulative variance contribution rates of each dimension were from 52.92% to 69.37%, which achieved more than 50% of the approved standard, and all the items held factor loading >0.5 in its relevant common factor, it had good construct validity. The scale had a good content validity, the r values between each dimensions and total scale were range from 0.57 to 0.81, P<0.01. For the high-score group, scores for social trust, social reciprocity, social network, and social participation dimensions were 32.89±3.19, 25.65±3.48, 38.27±6.59, 119.94±36.61, respectively, which were higher than low-score group (27.77±3.58, 20.18±2.91, 30.40±6.13, 96.76 ± 43.60), t-values were -24.23, -27.46, -19.90, and -9.24, respectively, P<0.001. It had good discriminant validity. The Cronbach'α coefficient for the total scale and four dimensions were from 0.76 to 0.86, and whose split-half reliability were from 0.68 to 0.84. Conclusion The validity and reliability of C-PSCS were excellent, and could be used to evaluate the social capital situation on the Chinese primiparas.