In this paper, we made a detailed comparison of "Shaki-shu" between "Shoki-shu" and "Shomei" to analyze their substantial characteristics. The results are the following. 1) Both books have little technical difference. 2) Some descriptions found only in "Shoki-shu" are merely omitted in "Shomei", and "Shoki-shu" made no spetial alteration and addition. 3) Some descriptions found only in "Shomei" are classified in parts which "Shoki-shu" carelessly omitted and in parts which "Shomei" deliberately revised and added in later ages. 4) Those deliberate alterations were made with the systematization of "Shomei", which are evident in the change of composition order.
