Check-in/check-out (CICO) is a Tier 2 behavioral management system in the School-wide Positive Behavior Support (SWPBS) framework, which is widely used in Western schools. However, this system is not currently used in public schools in mainland China, mainly because of the large class sizes. This study redesigned CICO to facilitate its implementation in schools in mainland China. This new intervention, which we call team leader-mediated check-in and check-out (TLM-CICO), combines the CICO system and the Chinese team leader system. We used an ABAB reversal design to evaluate the effects of TLM-CICO for three fifth-grade students who exhibited off-task behavior and varying degrees of problem behavior. The results indicated that there were functional relationships between the intervention and on-task behavior in teachers' instruction and self-study. The three teachers who implemented the TLM-CICO generally accepted the intervention and expressed their intention to use this system in their future classroom management. We also discussed the implications of the results, limitations of the study, and future directions.