In order to clarify the effect of unburnt pulverized coal (UPC) on coke pulverization properties. A series of fundamental experiments were carried out at laboratory furnace. The main results obtained are as follows: (a)Under the same temperature,coke fines increases remarkably with the progress of gasification for an hour, but after UPC was injected into coke layer, coke fines decreases; (b) Under the same temperature, Strength of coke increases after the reaction and coke fines decreases as the amount of UPC being injected into coke layer increases.