Inorganic additives could cause effective nutrient of compound fertilizer to decrease in the course of processing and storing. In ordered to solve the problems, the experiment of effective nutrient content changes in the course of processing and storing with different N,P,K fertilizer raw materials and inorganic additives was conducted. The research result indicated that grey bentonite, light red bentonite and calcium carbonate powder would have effect on effective nutrient of compound fertilizer. Inorganic additive should be chose by actual production.