This study was designed to show how ancient Chinese understood the concept of truth through characters listed in Shuowen Jiezi, the first analytical dictionary of Chinese characters (A.D.100). In my previous research, I examined the interconnectedness of „zhen‟ (貞) and „zhen‟ (眞) as cognate words, to show how ancient Chinese developed a concept of „truth‟ early on. In this paper, I would like to clarify how ancient Chinese thought about truth/falsehood, right/wrong, and assent/dissent through interpreting the meaning of characters with shi 是 („true‟) or fei 非 („false‟) as a components in Shuowen. I analyze shi 是 („true‟), 25 characters having 是 as a component (2 characters having 是 as a semantic part, 23 characters having 是 as a sound part), fei 非 (false), and 35 characters having 非 as a component (5 characters having 非 as a semantic part, 30 characters having 非 as a sound part). I further analyze fú 弗, signifying „not‟, and 17 characters having 弗 as a component (17 characters having 弗 as a sound part and 0 character having 弗 as a semantic part), because 非 and 弗 are similar in meaning and usages. Taking into consideration all the different meanings represented by these characters, I divide them into three categories: (1) characters for depiction of the object in question with distinctive features, (2) characters for regulation, and (3) characters representing value. The first category include 14 characters having 是 as a component (56%), 3 characters having 非 as a component (16%), 1 character having 非 as a component (6%). As the second, 4 characters having 是 as a component (16%), 23 characters having 非 as a component (66%), 4 character having 非 as a component (24%) are included. 5 characters having 是 as a component (20%), 3 characters having 非 as a component (9%), 12 character having 非 as a component (71%) are classified as the third. I hope this paper is to stimulate related research by providing the origins, historical development and detailed interpretation of truth-related characters, and so be able to advance toward more insightful writings on truth.