Abstract: According to differences in calculation principles, modes and processes, evaluation methods for oil and gas resources can be classified into three major categories, namely genetic methods, statistical methods, and analogical methods. These three types of methods can be further divided into subcategories. By studying the nature and the key problems of different evaluation methods for oil and gas resources, it is believed that genetic methods can be considered "simulation methods" in nature. Each genetic method has its own computing focus and calculations can be viewed as a "gradually decreasing" mode. Meanwhile, statistical methods estimate oil and gas resources through analyzing data, so they can be called "data methods". Their calculation processes can be viewed as a "gradual increasing" mode. Lastly, analogical methods determine the degree of enrichment of oil and gas resources in the prediction area based on the area's similarity with respect to a calibration area. The calculation results are often influenced by some sensitive parameters. These methods are "subjective cognition methods" and their calculation processes can be viewed as a "median". Some suitable evaluation methods must be selected in order to enhance reliability in different evaluation or exploration areas. This paper also discusses a new way to integrate resource amounts. This interval method can be used to more intuitively analyze resource coverage and enhance the accuracy of the final results.

Key words: resource evaluation, evaluation method, genetic method, statistical method, analogy method, method suitability