The appraisal of oil-gas composite geochemical anomalies is the most important key link in oil-gas geochemical survey and has a vital bearing on the evaluation of oil-gas potential and prospective prognosis of an area. In the past, conditioned by various factors, geologists could merely make qualitative evaluation for various geochemical conposite anomalies and, as a result, quantitative data were lacking. To solve this problem, the author has utilied lots of techniques including integrated indices for appraisal and fuzzy mathematics. The researches performed in three typical experimental areas have yielded satisfactory geological results, thus demonstrating the feasibility and effectiveness of these methods.