Abstract: The t₂ distribution of rock nuclear magnetic resonance can well reflect the feature of rock pore structure. But by transfer relation between the t₂ distribution and the mercury injection curve, it is hard to get the unified coefficient value, leading to big errors in application. This paper presents the standard physical model based on the relaxation mechanism of rock nuclear magnetic resonance, determines the transfer coefficient between t₂ and pore radius and develop the mathematical transform model between them through image and nuclear magnetic resonance analysis. This model provides a new method for rock pore character analysis, by which good applied results are gained.

Key words: nuclear magnetic resonance, rock pore structure, pore size distribution