Perusahaan memiliki salah satu aset terbesar. Dalam perusahaan manufaktur, siklus partisipasi merupakan siklus yang memiliki hubungan sangat kompleks terhadap siklus transaksi transaksi lainnya. Penelitian ini dirancang untuk mendukung pengendalian internal siklus persiapan pada PT. Surya Toto Indonesia, Tbk. Penulis menilai pengendalian internal berdasarkan COSO (komite organisasi sponsor) untuk menganalisis hasil persetujuan antara pengendalian internal berdasarkan persetujuan COSO (komite organisasi sponsor) dan mengendalikan internal pada perusahaan. Faktor utama dalam persyaratan PT. Surya Toto Indonesia, Tbk untuk memenuhi kebutuhan pelanggan, oleh karena itu PT. Surya Toto Indonesia, Tbk. Harus meningkatkan pengendalian internal dalam perusahaan untuk meningkatkan efisiensi dan meningkatkan operasional perusahaan. Tujuan penelitian ini untuk mempelajari sistem dan prosedur pencatatan siklus persiapan serta kelemahan dalam perencanaan internal perusahaan. Jenis penelitian ini menggunakan studi kasus jenis kualitatif, data diperoleh melalui wawancara, observasi dan dokumentasi. Sumber data yang digunakan penulis menggunakan data primer. Hasil penelitian penulis membuktikan bahwa PT. Surya Toto Indonesia, Tbk telah menerapkan pengendalian internal berdasarkan persetujuan COSO secara efektif. / Inventory has an important role in a company because inventory is one of the biggest assets, In manufacturing companies, inventory cycle is a cycle that has a very complex relationship to the cycle of other transactions. This research aims to evaluate the internal control of the inventory cycle at PT. Surya Toto Indonesia, Tbk. The author evaluates internal control based on COSO (Committee Of Sponsoring Organization) framework to analyze the results of a comparison between internal control based on COSO (Committee Of Sponsoring Organization) framework and internal control on the company. The main factor in the inventory of PT. Surya Toto Indonesia, Tbk is to meet customer needs. Therefore, PT. Surya Toto Indonesia, Tbk must improve their internal control within the company to improve the efficiency and effectiveness of the company's operational performance, especially reducing the level of losses incurred by the company and reducing the risk of fraud in the company. The purpose of this research is to determine the system and procedures for recording inventory cycles as well as weaknesses and strengths in the company's internal control. The type of research is conducted using qualitative data types. This data is obtained through interviews, observation, and documentation. The data source used by the author is primary data. The author's research results indicate that PT. Surya Toto Indonesia, Tbk has implemented internal control elements based on COSO (Committee Of Sponsoring Organization) framework effectively.