Abstract: Leaf protein (LP) is extracted from fresh leaves and stems. The resource of LP is very rich in China. LP production will loosen the short supply of feed protein.The paper studied the extraction technology of LP by heating method. The purpose was to find the suitable processing methods for increasing the protein content (PC) in the LP concentrate. The PC variation curve versus salt content at 0.1　％～0.6 % ,which is in the added water ,was obtained. The highest PC 58.8　% was gotten at salt content 0.2% . The test acquired a curve of the PC versus coagulative temperature (CT) at 60～90　℃. It is that as higher CT as higher PC. The obvious increasing is located at CT at 60～70　℃. PC increases 0.727　% with average increasing 1　℃. The LP content increases slow down. It is only 0.0775　% ,when the temperature increases at 70～90　℃. The orthogonal test on LP content versus added water, salt content, pH and CT was conducted. The decreasing order of the factors effecting PC was arranged by the R chart . That is salt content >added water>pH>CT. A potential curve was drown which show the four factors how effect the LP content. In order to reduce the energy consumption, a combined optimum processing condition is salt content 0.2　%, fresh plant∶water added =1∶2, pH 10, CT 70 ℃. It gain PC 63.76 %.