This paper has written on Hybrid tractor for power train system. The tractor industry is facing to a big problem about rising gas price and exhaust gas environment. Because it was possible overcoming the past drawback, Hybrid vehicle had been decided as the best technical way since it has started operating the internal combustion engine with the electric power as the motive power. to make it applicable technically, I have designed the model of a major power transmission factor. the simulation realized in this paper will show the process of tractor being turned by torque and force of each joints