T The agricultural sector is one sector to help the national economy, by increasing agricultural production, it is necessary to have a good irrigation system. Currently, the irrigation system in Indonesia has undergone several changes due to natural disasters, less than optimal irrigation management systems and Operation and Maintenance (OP) for irrigation infrastructure and even the area of ​​irrigation areas is decreasing due to land conversion. This research was conducted in the old irrigation area, namely Molek Irrigation Area (DI) in Malang Regency, East Java which was built in 1901 to irrigate an agricultural area of ​​3,971 ha. The irrigation system development and management required the Irrigation Modernization Readiness Index (IKMI). However, the existing IKMI assessment tends to be used for new irrigation areas so that if the IKMI is realized in the old irrigation area, the value of the old irrigation performance will decrease. Under these conditions, it is necessary to conduct research on the development of irrigation system performance assessment based on IKSI. This assessment development method is carried out using the Analytical Hierarchy Process (AHP) on the performance of the irrigation system based on IKSI. The results of the analysis in this study, (i) the performance of the irrigation system at Molek Regency reached 75.78%, which consisted of Aspect I of Physical Infrastructure 37.06%, Aspect II of Planting Productivity 13.77%, Aspect III of Supporting Facilities 5.78%, Aspect IV Personnel Organization 9.92%, Aspect V Documentation 3.35% and Aspect VI WUA 5.9%. So that the performance of the DI Molek irrigation system is in the good category. (ii) Development of irrigation system performance assessment in irrigation modernization readiness needs to add variables assessed, namely management system, management institutions and human resources so that the weighting of the new irrigation system performance assessment becomes: Physical Infrastructure = 0.051, Planting Productivity = 0.050, Supporting Facilities = 0.025, Personnel Organization = 0.013, Documentation = 0.011, WUA Condition = 0.017, Management System = 0.236, Management Institution = 0.381 and Human Resources = 0.217. (iii) Based on the implementation of the results of the development of the performance assessment of the new irrigation system, it is necessary to pay attention to a. Management Institution: Water Reliability, Facilities and Infrastructure and Human Resources, b. Management System: Primary Network OP, Secondary Network OP and Tertiary Network OP and c. Human Resources: Leadership Quality, Staff Quantity, OP Quantity and WUA Quantity. The parties that need to be involved in improving the performance of the new irrigation canal system are Parties involved in the Irrigation Commission, including: Central Government (Ministry of PUPR = Balai Besar/River Area Center, Ministry of Agriculture, Ministry of ATR/BPN) , East Java Provincial Government (SDA Office, Agriculture Service, Land Service), District/City Government ((SDA Service, Agriculture Service, Land Service), OP Officer, Weir Officer and Water User Farmers Association (P3A).