When lubricants is used under severe running conditions, their tribological characteristics are very important. We have studied the lubricating oil viscosity, kinds of additives and their amounts, and lubricating oil temperatures were changed. In order to study the effect of oil temperature on the wear of the surface, the temperature of the oil was changed for the same sample. Moreover, the temperatures of three kinds of oils which have very different viscosities at room temperature, were varied between 6$0^{circ}C$ and 115$^{circ}C$ while the oil viscosity was unchanged. It was shown from the test results that surface wear is not greatly affected by the amount of ZnDTP (Zinc dialkyl dithio phosphate) antiwear agent, but EP (Extreme pressure) additives are less effective against wear than ZnDTP additives. The viscosity of lubricating oil and its temperature greatly affect the wear of the surface. Combining all the wear data with those of the surface strength, it was observed that the higher the load, the wider the scratching of wear, and also in the case of the same running load, the lower the wear, the longer the life of the surface strength.