Abstract For a student in normal college, espically a feature elementary teacher, knowing Number Theory is necessary. Number Theory includes everything related to number. It has easy parts like adding, counting, factorizing,…etc, but also has difficulty parts like Euler faction, perfect number,...etc, How to help student to learn what they want is one of the purpose of this paper. We did following things in this paper. (l) Using one of the software, HyperCard, of MAC to produce a CAI teaching material. (2) Establish the process by showing how to make a topic of Number Theory, Fibonacci sequence, into CAI teaching material. Hopefully, at very near future, each part of Number Theory could be computer-aid-instructable.