On the basis of the single-ion model, a method of calculation on the magnetizati on curves for magnetically aligned rare-earth-Fe(Co) intermetallic compound is d eveloped. High-field magnetization curves for magnetically aligned Nd2Fe14B and Pr2Fe14B were calculated by using th e above method. In the calculations, the fitted exchange and crystalline field p arameters from magnetization curves of the single crystals were used. The calcul ated curves agree well with the experiments.