From the geology exploration borehole data in the mining areas 76 and 78 of Wuyang Mine, eleven reliable boreholes are selected, together with data related with five influencing factors of the gas content, including the buried depth of the coal-bed, the rock properties of the coal seam (the ratio of the sandstone to the mudstone in the 30m coal seam roof and floor), the coal thickness, the geological structure and the degree of the coal metamorphism (volatile matter and ash). Two kinds of gray relational analysis methods are used-the Deng's relational degree and the generalized relational degree-- to study these influencing factors of the gas content in the coal seam under the condition of without mining, and the GM(1,7), GM(1,6) and GM(1,5) gas content prediction models are established. The results show that, for the case without mining affecting the coal seam, in the mining areas 76 and 78 of No.3 Wuyang Mine, the ratio of the sandstone to the mudstone in the 30m coal seam floor, the geological structure, the volatile matter and the ash are four main influencing factors of its gas content. The GM(1,5) gas content prediction model built by the four factors enjoys the highest prediction accuracy, which can be used to predict the gas content in cases without mining affecting coal seam in the mining areas 76 and 78 of No.3 Wuyang Mine. The predictive value can provide the basis for the prevention and the treatment of coal mine gas disasters, and also has important practical significance for the mine safe production.