The main problem of controlled release fertilizer on the market is that the brittleness increased after sulfur solidification, causing sulfur coated controlled release fertilizer seriously unshell. In existing production processes, coat the outer membrane of sulfur with thermosetting resin, microcrystalline wax or epoxy eased the problem, but there are still shelling phenomenon, affecting the release fertilizer effect. Dendritic polymer (CYD-CR236/CYD-CR486/CYD-CV236/CYD-CV486) used as toughening agent has very distinct advantages: 1) the effect is obvious, the impact strength and tensile strength were increased by 512% and 187%, and didn’t lower the glass transition temperature and elastic modulus, to achieve toughening effect; 2) this kind of toughener can serve to strengthen the membrane material sealing effect, to avoid spraying sealant, thereby reducing coating steps; 3) process is simple, suitable for current existing sulfur coated device, without any additional equipment. Weihai CY Dendrimer Technology Co. Ltd.-Professional Manufacturer for low cost dendritic polymers.