A color printer wherein densities of blue, green and red colors of an object copied print with respect to an original color picture for setting standard copying conditions by using the original color picture, a copied print is made by using the original color picture for setting standard copying conditions, densities of blue, green and red colors of the copied print are measured in an optical path of copying exposure, and the standard copying conditions are set on the basis of the functions of the measured densities of the object copied print and the copied print.