Koperasi Karyawan Kusuma Mulya PT Kawasan Industri Wijayakusuma (Persero) is cooperation enganged in saving and loan businesses, shop businesses and multi-purpose businesses. Management of saving and loan transactions is carried out using a conventional system so that it cannot detect errors in recording saving and loan of cooperation members, it cannot detect multiple loans, and saving and loan reports are not presented on time. Conventional financial reporting is possible errors in recording financial transactions and financial statements are not presented on time. In addition, the absence of standard account in making financial statements results in inconsistencies in the presentation of financial statements between accounting periods. The aim of this research are to design and build computerized accounting information system that produces saving and loan informations and financial statements that are accurate, informative, timely and accountable. The system development method used is prototyping method with system modeling using unified modelling language (UML). System development using hypertext preprocessor (PHP) programming language and MySQL database. The results of this research are the creation of a web based accounting information system application, especially the savings and loans and the financial statements subsystem that can solve the business process problems at Koperasi Karyawan Kusuma Mulya.