This paper reports on the researches concerning the initial stresses in concrete.At first, in order to predict the shrinkage and the initial stresses in concrete, the graphical and numerical computation are described. And then, as one of the measuring methods of the initial stress in concrete specimen that has been exposed to the air, procedures and results of the whittling and erasing methods are stated. Test results are in accordance also with the decrease of bending strength of the similar specimen.In general, the intensity of the initial stress at the surface of the specimen is found to be about 20kg/cm2 (tension) in mortar, and about 15kg/cm2 (tension) in concrete.