Abstract: The study of the coal correlation in Yenan Formation （Ningsia Region） reveals that there are obvious differences among several main coal beds as 2,6,7,14,17 of the research area, in the characteristics of some organic geochemical parameters such as, "A"％, I_H, potential hydrocarbon, the distribution of n-alkanes and the consitution of alkylphenanthrenes. It seem to depend on the condition of oxidization-reduction;the degree of coalification and the type of raw organic matter. It is possible to make coal beds themselves become correlation mark ones.