Objective: This study aimed to explore the correlation between the two patients by measuring the rumination and the status of career maturity in clinical practice nursing students, and to provide a basis for the formulation of targeted intervention measures to improve the career maturity of the nursing students. Methods: A cross-sectional survey was conducted in this study. With the stratified convenient sampling method, 868 nursing intern students were selected from twelve hospitals in Nanjing through June to December 2018.The general data questionnaire, The Career Maturity Inventory (CMI) and the Ruminative Response Scale(RRS-10) were used. Results: The average level of occupational maturity of 868 clinical nursing students was (3.07±0.28), in the middle level; The average level of rumination was (22.71±4.70), among which brooding (12.05±2.58) was higher than reflective pondering (10.67±2.48); Nursing students' rumination were related to career maturity (P<0.05). Conclusion: The nursing students in clinical practice mostly have rumination which affect their career maturity. In the teaching of clinical practice, nurses should pay attention to students' mental health and the status of ruminant thinking, pay attention to the vocational development planning education of the nursing students, take measures to guide the students actively and advantageously, and then improve their career maturity level.