Abstract: Shale gas is abundant in widespread continuous organic shale with low porosity and ultra-low permeability.Commercial production is possible after horizontal well fracturing. The above characteristics limit geological understanding, and result in a high uncertainty for reservoir parameters and reserve calculations.We propose a quantitative evaluation method to resolve the uncertainties through a static evaluation model and expectation curve analysis by using a probabilistic method. It offers a better solution for reserve parameters and reserve calculations, and provides a reference method for reserve evaluation, exploration planning and development, and shale gas production.