Objective: To investigate the status of social support and it’s influencing factors. And to provide scientific evidence for preconception care, mental intervention and improving mental health of preparing pregnant women. Methods：454 preparing pregnant women were investigated by questionnaire which based on Social Support Rating Scale made by Xiao Shuiyuan. And all collected data were statistical analyzed by SPSS21.0 software. Results: In general, preparing pregnant women reported that they had received the mediate social supporting, but objective social support was lower. Specially, 57.9% of preparing pregnant women had the low level objective support. level of support availability of most of them were mediate or high. And 63.7% of them had experienced the high subjective social support. Finally, the results of multiple linear regression analysis showed that main influence factors of social support were relationship with their parentsinlaw and gravidity, and the total contribution rate was 10.6%. Conclusion: Preparing pregnant women have lower level of objective social support. The relationship with their parentsinlaw and gravidity are the most important factors of social support.