Abstraet-Scrum as one of a popular agile frameworks is quite flexible to changes. However, this behavior is accompanied by several shortcomings, especially the documentation section since its dependence on direct communication. Therefore, the use of knowledge management in Scrum seems to be important. Knowledge management in Scrum was influenced by several challenges such as the various locations of the team members, the changes of software developers, the methods for large-scale projects, and the needs for high-quality software. These problems need to be resolved to avoid the amount of knowledge loss. Therefore researchers want to find out more about how knowledge management system influences the development of scrum-based software and its effect on developers' performance. This study uses a quasi-experimental approach with the application in the real world to startup companies. A quasi-experimental is research method used to compare the effect before and after treatment in a group by comparing the performance conditions before and after the implementation of the knowledge management system. The data collected from experiment are scrum artefact, knowledge artefact, and developers' performance (using IWQP). The first experiment for the group lasted for two sprints using a scrum support system. Knowledge management system based scrum used for the second experiment. The findings obtained were an increase in adaptation performance of 8%, contextual performance of 12%, and improvement of knowledge circulation from the development team. The Knowledge Management System is proven to be able to improve and handle the knowledge circulation in Scrum and give impact to software developers.