Abstract: For the gear transmission,which is adopted in most mechanical equipment,there are agreat number of worn particles of different size in the lubricating oil,so the effects of the particles,both mechanical and thermal,are not allowed to be neglected.The mechanical effect can produceabrasive wear,while the thermal effect can lead to scuffing failure of gears. The mechanism of theparticle induced scuffing failure has been preliminarily realozed but the corresponding calculationmethod and model have not ever been established, nor the experimental analysis method beenreported.Thus,a mechanism and calculation method are presented in this paper for tbe scuffingfailure of gears lubricated with particle-containing oil,and furthermore experiments are conducted.Under the given conditions,the comparison experimental results of gears,lubricated with particle-containing oil and pure oil respectively,shown that the scuffing failure load obviously decreased dueto the existence of particles,and the larger the particle size,the shorter is the scuffing failure time.Using the proposed model,the calculation of particle effects(such as load sharing,temperature)was made,and the theoretical results agree well with the experimental results. Therefore, thecalculation model not only facilitate to realize the particle effects as well as the scuffing failure ofgears,but also can be widely applied.