The effect to control Ceratocystis fimbriata of sweet potato is different for different consistence IWMPA solution (Intermixture With Mancozeb and Phosethyl Al), It has the more good effect for the more high consistence,833ppm; washing the root of sweet potato to soak IWMPA solution for 10 minutes, effect to control Ceratocystis fimbriata of sweet potato is reduced; Prolong the time of soaking in solution can raise defence ill effect, the temperature of solution does not produce influence basically for the effect of medicament; It is very bad for effect to dip in medicament with the sprout of sweet potato, only is 19.8% . It is better to dip medicament with the root of sweet potato