The supergene karst reservoir，regarded as the research target by drilling，develops 100 m thick below the top of the carbonate buried hill in Nanpu sag. The residual karst index is firstly introduced as a quantitative parameters for evaluating the effectiveness of supergene karst reservoir space in the study area，taking advantage of seismic data，core，thin sections，electron microscope（SEM），well logging，mud logging and oil test data and combining with diagenesis types and degree，classification of reservoir space，physical characteristics and pore structure types. As a result，the supergene karst reservoirs of carbonate buried hill in Nanpu sag are divided into 3 types of I，II and III and evaluated comprehensively. Average amplitude，average instantaneous frequency and amplitude distorted degree，which are better correlated to residual karst index and independent to each other，are selected to be clustered and then mapped. At last，the supergene karst index contour map is drawn and then is verified with the actual drilling data. It is found that the accuracy rate is more than 70%.Finally，the favorable zone prediction of the carbonate supergene karst reservoir in Nanpu buried hill is realized，which indicates the direction for the next exploration and deployment.