Abstract:This article details the usages of quantization theories Ⅰ and Ⅳ, and the matters needing attention. The quantization theory Ⅰ(simple method)is used to predict reference variable (dependent variable or gaswell production) from the terms (descriptive variable) of observation sample. Quantization theory Ⅳ is used to class wells by analysing the geological informations of gas wells and the seismic informations nearby the gas wells when there is no reference variable. The two quantization theories were used to make hydrocarbon prediction and classification of 38 drilled wells which penetrate Yangxin series of Permian system in south Sichuan. The prediction success rate of quantization theory Ⅰ is 79%, and that of quantization theory Ⅳ is 87%, the latter being higher than the former. However, no matter which quantization theory is used, the prediction effect mainly depends on the optimum pickup of geological and seismic factors.