In the stage of exploration, to remedy good evaluation of the reservoir characteristics, to decrease exploration risk and investment, it is necessary for us to erect a geological knowledge base in order to remedy disadvantage of the lack of data. This is because, in this stage, there may has bad ground conditions, sophisticated underground geological situations and rare wells. To do this, suitable outcrops should be selected as the experimental area of the field reser voirs. By the analysis of the outcrop profile and the sedimentary face correlati on, we can make sedimentary models so that the distribution of faces in different time can be defined. At the same time, the tracing of the sandstone outcrop in  the profiles and the analysis of the compositional factors can make the models  of the original sandstone framework. Subsequently, with the combination of loggi ng and drilling data, the geological prediction model of reservoirs can be made  through the random modeling method. On doing this, prediction of the sandstone s uperimposition between different wells in space and the interbed distribution ru les can be realized on account of certain geological laws. Kuche Depression is l ocated in front of Tianshan Mountain. The tectonic and ground conditions are very complicated; seismic imaging in the mountain areas and signal-to-noise ratio are low; drilling in these areas is of unexceptionally difficult. Due to all of  these reasons, it is very important to make geological models of reservoirs. Th is method has been used in the reservoir description in Tuziluoke gas field succ essfully. For the evaluation of the reservoir quality and potentiality in the ga s field, it is a reliable method.