The development of Information Technology (IT) can increase the competitive advantage of an organization, so that many organizations rely on IT, including SMK Tunas Harapan. In carrying out its service activities, SMK Tunas Harapan is supported by a Library Information System. The concept of Information of Technology (IT) governance is a way of managing the use of information technology in an organization. IT Governance combines good practices from planning and organizing, developing and implementing, distributing and providing services, as well as monitoring information system performance to ensure information and technology can support organizational goals and missions. One way to know this is by conducting an audit and analyzing the system. COBIT (Control Objective for Information and Related Technology) is an IS control standard that is general in nature and can be accepted and implemented by organizations. This study aims to analyze the information system of the Tunas Harapan SMK library by analyzing its internal control using the COBIT framework. The IT Maturity Model is a model used to measure the maturity level of information technology management in an organization, which includes: level 0 (non-existent), level 1 (initial), level 2 (repeateable), level 3 (defined), level 4 (managed) and level 5 (optimized). The higher the maturity level, the better the information technology management process. In this study, using the domain delivery and support (DS) was chosen to perform analysis at each level of the IT COBIT process. From the results of this research, it is obtained that the maturity level of the Library Information System is at an average level of 2.67 (repeatable but intuitive) from the DS1, DS4, DS5, DS7, DS8, DS10, DS11 and DS12 domains.