Objective To understand the current status and influencing factors of breastfeeding duration among working women, and to provide reference for establishing breastfeeding support program for this population. Methods A total of 364 postpartum working women returning to work were selected in child prevention health clinic in 2 tertiary hospitals in Zhengzhou, and they were investigated using self-designed working women breastfeeding questionnaire. Kaplan-Meier method and Cox proportional hazards model were used to analyze breastfeeding duration and its influencing factors. Results Mean duration of breastfeeding of the postpartum working women returning to work was 11.94 months. Cox proportional hazards analysis indicated that, whether insisting on exclusive breastfeeding within 6 months after birth, anticipated breastfeeding time, whether continuing breastfeeding after returning to work were influencing factors of duration of breastfeeding(P<0.01 for all). Conclusion There is a gap between duration of breastfeeding among working women and the recommendation of WHO. It is necessary to improve exclusive breastfeeding within 6 months, help working women returning to work to formulate scientific and reasonable breastfeeding plans and goals, and take effective measures to improve breastfeeding support in the workplace, so as to create conditions for continued breastfeeding.