A set of hydrocarbon source rock exists in Guide depression. Up to now, it’s age assignment and exploration potential remains unclear, as a result, the exploration process of oil and gas in this depression was restricted. Based on the field reconnaissance, outcrop measurement, continuous electromagnetic profile(CEMP) and sample analysis, the paper draws the conclusion as follows: 1, According to sedimentary characteristics and sporo-pollen assemblage, combined with the regional geology data, the age of hydrocarbon source rock is thought to be Early Cretaceous with the sedimentary environment of shallow lake, semi-deep lake. 2, The scale of hydrocarbon source rock was determined on the basis of data from outcrop measurement and continuous electromagnetic profile(CEMP). 3, Through experimental analysis on sample including organic abundance and thermal evolution degree, comprehensive evaluation on exploration potential of the hydrocarbon source rock was made. It was considered to be act as effective hydrocarbon source rock in Guide depression, thus improves the hydrocarbon exploration potential. 4, finally, Based on the field investigation and continuous electromagnetic profile(CEMP), the paper discussed on source-reservoir-cap assemblage and pointed out the favorable exploration direction.