Admission of new students is an annual activity process that exist in educational institutions. In this process, educational institutions try to get the best students among the other candidates according to criteria determined by institutions. In the last 3 years, the Ministry of Education of Indonesia was implementing a new admission system in Elementary, Junior and Senior High School, namely zone system. This paper introduces an approach to optimize admission of new students based on zone system by using Knapsack Problem -Fuzzy Inference System (FIS) Tsukamoto. Specifically, final score was considered as the output for making decision in the admission and 3 variables were used as data input such as: average score of exams, distance, and age. Knapsack problem was used to determine allocation of quota of each region for admission based on average score of exams of all students in a region. Then, data input will be processed by using FIS Tsukamoto to determine the final score of each student. In the last step, rank order list of new students of every region was made. The results show that knapsack problem -FIS Tsukamoto model might be suitable and helpful for proper admission of new students based on zone system.