As employees change jobs more frequently and the cost of replacing employees increases,understanding and managing the socialization process will provide organizations with a competitive advantage.Thus,how to effectively retain human resources is still a major issue of concern.Especially for new employees,the transition to a new job or role is inherently challenging and stressful.Adequate resources are effective for new employees'adjustment and successful socialization.As an important resource holder,managers can foster the speed of new employees'adaptation by providing supporting resources.Supervisor developmental feedback refers to the useful information provided by the supervisor to enable the employee to learn,develop,and improve their work,and to improve the employee's work attitude and behavior.Based on the resource conservation theory,this study introduced supervisor developmental feedback into the special context of organizational socialization and characterized task performance and work initiative as the result of organizational socialization.Meanwhile,it developed the mediating mechanism of perceived insider status between supervisor developmental feedback and organizational socialization outcome.To further examine the positive meanings of supervisor developmental feedback to organizational socialization,this study explored a boundary condition of this association in order to understand the contexts under which the strength of this relationship may vary.In this study,we collected data from enterprises in Shanghai,Beijing,and Guangdong Province,mainly in service and manufacturing industries.Based on the three-wave data from 172 leader-employee dyads,we tested the hypothesis through data analysis by SPSS and MPLUS.The results showed that the supervisor developmental feedback can promote the new employee to form the perceived insider status,thus further improving the new employee's task performance and work proactivity.Core self-evaluation positively moderated the indirect effect of supervisor developmental feedback on task performance and work proactivity.Specifically,the above indirect effects are significantly strengthened when the new employee's core self-evaluation is high.The results have substantial implications for both practice and research.First of all,based on the resource conservation theory,this study takes the supervisor developmental feedback as an important resource,investigates the influence of the supervisor developmental feedback on the organizational socialization of new employees,and broadens the scope of application of the theory.Secondly,this study proves the validity of supervisor developmental feedback,which has a positive effect on new employee's identity and work behavior.Finally,this paper discusses the moderating effect of core self-evaluation which is a new employee's personal trait,and provides a more comprehensive view,namely,individuals with high core self-evaluation can make better use of the resources given by their supervisors to realize organizational socialization.In addition,findings of this study provide practical strategies for organizations to retain new employees.On the one hand,supervisors should focus on the form of feedback to new employees,in a developmental and supportive way to effectively promote the new employees to complete the role identities transformation and adaptation.On the other hand,supervisors should pay attention to the effect of new employees'personal characteristics on the process of organization socialization,and carry out targeted management measures.