The renowned polyglot Yuan Ren Chao has long been acclaimed as a gifted and versatile Chinese linguist with astounding background knowledge of physics, music and philosophy. Rarely have researchers discussed his status as the first Chinese scholar to have proposed “the scientific study of the sign”, chronologically after but provably independent of Ferdinand de Saussure, Charles S. Peirce and Lady Victoria Welby. In contrast to the favorable reception of many of his lauded works on linguistics, much less attention has been paid to the semiotic foundation upon which he accomplished most of his writings of linguistics. Since 1926, Chao had been working on such central subject matters of linguistics as meaning generation, phonology-syntax interface, script and so on, with a clear emphasis on the semiotic properties of the linguistic sign unfolded at all levels of speech production and understanding from allophones to contextualized interpretations of discourse. The present paper not only discusses the criticality of restoring the rightful place of Yuen Ren Chao’s works in its full semiotic framework, echoing the acclamation of Chao as the founding father of modern Chinese linguistic studies, but also carries out a critical in-depth contrastive analysis between Chao’s model of the linguistic sign, among those of many other non-linguistic multi-modal signs he had dealt with since 1920s, and the two classic models provided respectively by Saussure and Peirce. Accentuating the salience of his life-time semiotics-based work on language, among various other fields such as music, philosophy and cybernetics, this paper concludes by restating Yuen Ren Chao’s de facto status of being the founding father of modern studies of the sign in China.