The aim of the research described in the article is to address jargon numerals of the Chinese language that representatives of certain communities use for clandestine and facilitation purposes. The article analyses the ways and mechanisms of how jargon equivalents of numerals are formed and provides scrutiny, as well as a classification (including the one developed by the author). Moreover, the article studies the interdependence between the numeral substitutes and the realm of activities of their users. Over 70 sets of jargon numbers have been analysed. The work examines all present-day achievements in studies of jargon names of numerals that are currently available in Chinese linguistics and are the result of structural research. The author considers this vocabulary from the point of view of a linguistic semiotic approach and uses Charles Morris’s semiotic model. When numerals are represented by jargon, the functioning of the sign is as follows. The bearer of the sign is a jargon numeral that points to a certain number (the designatum). Depending on whether the interpreter possesses the necessary cultural knowledge, s/he is (or is not) subjected to influence, which results in making a connection between the bearer of the sign and the designatum. The article accumulates and analyses a great number of ways that are used to build jargon vocabulary. The classification of all registered ways is based on their division according to their graphic and phonetic forms, as well as in accordance with their conventional predicament, thus resulting in three groups. The first group includes the vocabulary which is based on the graphic principle, the second group on the phonetic principle, the third group on the conventional predicament determining the choice of the sign substitute. The analysis of the empiric material allowed the author to single out the peculiarities attributable to jargon numerals. Firstly, the sign substitutes are of a universal character of when one and the same sign substitute may be used in several sets of numerals (hence, in several professional communities). Secondly, jargon numerals are characterized by multifunctionality as one and the same sign substitute may denote several different numerals. Thirdly, sign substitutes of numbers (numerals) generally refer to ordinal nonspecific vocabulary, primarily of neutral axiological connotation. This is due to the need to make it easy for semiosis participants to remember them and to avoid attracting the attention of outsiders to the communicative process.