Organic-inorganic (minerals) controlled release material was used to modify urea and develop two new kinds of controlled release N fertilizers—modified urea. The result of potted plant shows that two modified kinds of urea are better than the normal urea under the condition of equal weight. XRD and IR were also used to analyze the crystal structure of the new kinds of modified urea, and found that their crystal structure changed greatly. It is the crystal structure change that increases the stability of modified urea.In this way we can raise the fertilizer efficiency and increase the utilization ratio of N.