Lack of collaboration skills can be seen from the ineffectiveness of learning in groups. This research aims to determine the increase in collaboration skills through the implementation of lesson study-based learning at Kemala Bhayangkari High School. This type of research is classroom action research. The subjects of this research were class X1 students who worked in groups. The instrument used was an observation sheet filled in by 3 observers. This research data is in the form of observations of collaborative activities carried out by subjects in their groups. Student collaboration is enhanced by using the Lesson Study strategy which facilitates collaboration between fellow educators in terms of planning, implementing and evaluating learning. The results of this research show that in cycle 1 and cycle 2 the collaboration indicators experienced enhancement. It can be concluded that there has been an increase in teacher and student collaboration at Kemala Bhayangkari High School as a result of implementing lesson study.