Japan was politically and culturally isolated from the world during Edo Period for over 200 years. Meanwhile Japan produced their own distinctive culture in art, literature, and academic research. Mathematics was also highly and uniquely developed in Japan at that time and it is now called “Wasan (Japanese math)”. The bestseller of Wasan was “Jinkoki” written by Mitsuyoshi Yoshida in 1627, which was widely read by Edo people and was used as a textbook of mathematics all through Edo period. In this paper, some contents are introduced from “Jinkoki” and their close relation to the modern mathematics education in elementary schools in Japan is revealed. We can even get some suggestions to mathematics education in the future from the concept and the spirit of “Jinkoki”.