In the first century, Sinographs and Chinese culture were transmitted to Japan, Korea and Vietnam, simultaneously had profound impact on countries they passed by, and then, formed the vast Sinographic Cosmopolis. During the contact with Sinographs and culture, the people of all three nations had created their writing systems that based on these elements of Sinographs. Based on script evidences recorded in Kokuji no Jiten, this article will analyze the characteristics and suggest the historical divergence of the Waji system (also called the Kokuji), conduct comparisons with the Vietnamese Nom script, develop the model of the structure of these scripts, and specifically point out the similarities and differences of these two writing systems.