Abstract: Objective To investigate the second fertility desire of married migrant women before and after the universal two-child policy,and examine the effect of the universal two-child policy on the second fertility desire of them. Methods This study used data from National Internal Migrant Dynamic Monitoring Survey in Guangdong Province in 2014 and 2016. Propensity score weighting analysis was conducted to balance the differences of covariates between participants interviewed in different years, and multinomial Logistic regression models were performed to examine the effect of universal two-child policy on second fertility desire among married migrant women. Results The second fertility desire of married migrant women was raised after the implementation of universal two-child policy, and for those who did not conform to the two-child policy before the implementation of the policy, the effect of the universal two-child policy was greater（OR_{not allow}=5.35,95%CI： 4.55-6.29; OR_allow=1.61,95%CI： 1.36-1.90）. Economic burden andchild care were the main reasons that impede their second fertility desire. Conclusion After the implementation of the universal two-child policy, the second fertility desire of married migrant women hasbeen significantly increased, but it still needs to be improved.The roles of alleviating the economic burden of reproduction and developing infant care services in improving the second fertility desire of migrant women should be explored in the future.

Key words: Fertility desire, Migrants, Universal two-child policy