Methods for measuring African Padauk logs, according to the ATIBT （Association Technique Internationale des Bois Tropicaux） Standard and the Chinese National Standard, are （described） in this paper. Due to the differences between the two standards, the calculated volumes of African Padauk logs, when based on the Chinese National Standard, are bigger than when calculated on the ATIBT Standard. The reasons that cause the increase in volume are discussed. Further analysis was focused on the relation between the diameter of one log and its increasing volume with the two standards. Results found that the rate of the increase in volume decreased as the diameter of the log increased. Thus, using the diameter of a log and the regression method, an exponential function, the increasing volume is able to be calculated. The authors suggests that it could be used to predict the volume difference of logs between ATIBT and the Chinese National Standards.