This study aims to test a cross-lagged model that explores the relationship between organizational socialization and the cooperative behavior of newcomers, along with the mediating role of perceived organizational support and perceived insider status. Questionnaire survey was conducted to collect sample data, and two-wave cross-lagged design with a 5-month interval was employed to verify the conceptual model. A total of 187 newcomers (female = 59.89%; average employment time = 9.3 months) were recruited, and the data was examined by cross-lagged structural equation modeling. The results showed that organizational socialization at T1 had a positive cross-lagged effect on perceived organizational support, perceived insider status and cooperative behavior intention at T2 respectively. Both perceived organizational support and perceived insider status at T1 had a positive cross-lagged effect on cooperative behavior intention at T2. In addition, perceived organizational support at T1 had a positive cross-lagged effect on perceived insider status at T2. The insights gained in this study may help to draw the attention of organizations on the organizational socialization and cooperative behavior of newcomers so as to enhance their subsequent performance.