Abstract: Objective To understand the current situation of nursing undergraduate students' sense of meaning in life,analyze the mediating role of positive emotions between positive rumination and sense of meaning in life,and provide scientific basis for improving nursing students' sense of meaning in life. Methods From June to August 2022,314 undergraduate nursing students in Beijing were selected by convenient sampling method. The questionnaire survey was conducted with the Chinese version of the meaning in life questionnaire（MLQ-C）,the rumination thinking scale for college students,and the positive and negative affect schedule（PANAS）,and the data were analyzed. Results The total score of the sense of meaning of life of nursing undergraduates was （50.88±8.71）points,of which the score of the dimension of seeking sense of meaning was （27.04±5.25）points,and the score of the dimension of having sense of meaning was （23.83±5.46）points. Positive rumination,positive emotions and sense of meaning in life were positively correlated（r=0.442,0.496,both P<0.01）.Positive rumination was positively correlated with positive emotions（r=0.619,P<0.01）. The mediating effect test results showed that positive emotions had a partial mediating effect between the sense of meaning of life and positive rumination among nursing undergraduates,and the mediating effect accounted for 63.02% of the total effect. Conclusion The level of sense of meaning of life of undergraduate nursing students is in the middle and upper level.Active rumination can directly affect the sense of meaning of life of nursing students,and can also indirectly affect the sense of meaning of life of nursing students through positive emotions. Nursing educators can improve the positive emotions of nursing students by cultivating their cognitive style of active rumination,so as to improve the level of sense of meaning of life.

Key words: Undergraduate nursing students, Sense of meaning of life, Positive rumination, Positive emotions, Mediating effect