Abstract: Rock mechanical characteristics are not only the basis for the rock classification,but also the guidline of selecting bits and drilling prameters.Predicting the rock strength characteristics is the key for optimum field drilling operations.This paper discusse a method to predict the rock strengh characteristic,such as drillability,hardness,plastic and shear strength,by means of the elastic sonic principle and logging data.The rock mechanical characteristics profiles have been estabilshed by means of this method mentioned above in partial block of Tuha oil field.