Introduction
1．Divisibility
2．Greatest Common Divisors and Least Common Multiples
3．Prime Numbers and Unique Factorization Theorem
4．Indeterminate Equations (I)
5．Selected Lectures on Competition Problems (I)
6．Congruence
7．Some Famous Theorems in Number Theory
8．Order and its Application
9．Indeterminate Equations (II)
10．Selected Lectures on Competition Problems (II)
Appendix: Answers of Exercises
