R. P. Ojdrovic proposed the method for predicting the long-term drying shrinkage of concrete from the results of short-term tests on 15 cm diameter cylinders. However, Only American Concrete Institute (ACI) model equation was investigated in this study, and investigation on the effect of specimen size was not conducted. Therefore, in this study, Comite Euro International Du Beton (CEB) model, Architectural Institute of Japan (AIJ) model, and Japan Society of Engineers (JSCE) model equations are investigated in addition to ACI model equation, and the effect of specimen size was investigated too. Results show that the accuracy of prediction of the long-term drying shrinkage increases significantly when the shrinkage data at 56-day are used to adjust the models, and the test-adjusted AIJ model are more than predictions using other adjusted models.