Abstract: Basic classifications and evaluations of the Cenozoic semi-diagenetic rock masses are carried out by using the engineering rock mass classification methods in the current codes, on the basis of analyzing and summarizing the geological and engineering characteristics of the Cenozoic semi-diagenetic rock masses. It is found that the engineering rock mass classification methods in the current codes have strong universality for most engineering rock masses, but the applicability for the special medium between "rock" and "soil" is not universal. It is difficult to highlight the engineering characteristics on the influence of the engineering construction. According to the theory of engineering geology, the applicability of the engineering rock mass classification methods in the current codes to the Cenozoic semi-diagenetic rock masses are further analyzed and evalerated. On the basis of summarizing the previous research on the engineering characteristics and classification of the soft rocks as well as the Cenozoic semi-diagenetic rock masses, the idea and suggestion of engineering rock mass classification evaluation of the Cenozoic semi-diagenetic rock masses is put forward.