Abstract：All previous automatic identification methods for logging microfacies mostly emphasized on mathematic statistical analysis or adopted a few mathematic parameters for identification，therefore they can't fully reflect the logging characters on a depositional environment. The paper took the train of thoughts using all key logging facies elements that reflect the depositional environment for model building and identification from angle of contributing factors in deposition,built multiple mathematic models using 9 key logging facies elements (log amplitude，pattern，etc.)for quantitative description;then the model building was conducted for each microfacies according to the key logging facies elements (especially to characteristic logging facies)respectively by using optimal log of logging facies (characteristic logy，and accordingly using the key logging facies elements taken from logs of different wells for identifying logging microfacies. So the mathematic method for quantitative identification of logging microfacies has been fully and effectively constructed.
