Abstract: Functional genes could be qualitatively analyzed by real{{{\hyphen{}}}}time fluorescence PCR, but there is still much to learn from the qualitative data to qualitative reservoir prediction, especially great significance to the exploration of subtle reservoirs. Suganhu basin was studied in this work, which has the features of low exploration degree. 191 samples was collected with the interval of 1{{\hyphen{}}}4 km and the depth of 50 cm. Then the numbers of methane, propane oxidation bacteria functional genes ({\it pmoA}, {\it prmA}) in the samples were measured. Furthermore, based on the cumulative probability distribution and regression analysis, the anomaly grade classification system has been built, combing the anomaly zone with the strata interpreted by geophysical exploration, the favorable exploration areas of oil and gas in Suganhu basin were delineated. The results indicated that: the cumulative probability of {\it pmoA}, {\it prmA} nearly conform the 4\textsuperscript{{\it X}} $\times$ 10\textsuperscript{4}, 2\textsuperscript{{\it X}} $\times$ 10\textsuperscript{4} copies/g index distribution respectively, The natural numbers as 1, 2, 3, 4 were assigned to these two equations, thus obtained 4, 16, 64, 256 and (2, 4, 8, 16) $\times$ 10\textsuperscript{4} copies/g to divide the anomaly grades to four: low, medium, high and super. Anomaly zones above the medium level distribute in the east, west and central of basin, the medium anomaly zones in the east and west distribute slightly north of Permian and Jurassic strata, the medium anomaly zone in the central distribute between the two strata, these three medium anomaly zones above were delineated as the favorable exploration area of the~basin.