Abstract: Based on the State Language Commission’s“general balanced corpus of modern Chinese”and using the software such as Microsoft Access and SPSS, this paper has made a quantitative comparison of 55 characteristics between the linguistic styles of special and popular sciences and technologies. The result shows that significant difference exists in 49 characteristics. It finds a large number of medium frequency words used in the special scientific and technical style, different from the general styles in the relationship between the morphologic coverage and the overused words. Circumstances decide a language’s characteristics. As special scientific and technical（SST）style and popular scientific and technical（PST）style share similar living and background environments, they share similar linguistic characteristics: regular written form; with overlapped communicative purposes, addressers, and topic areas, both as scientific and technical（ST）style distinguished from other styles. However, as the two styles have different participants, relations between participants, channels, communicative purposes, and topic areas, thus the difference in 49 characteristics.

Key words: ST, SST, PST, corpus