Abstarct: The formation of asphaltine precipitate during the production and process of the natural and synthetic hydro-carbons is known as a problem all around the world. Extensive studies has been done by researchers in order to identify the cause of asphaltine precipitation in oil before performing any action for its separation. The reason for this is the change in the thermodynamic conditions like change in crude oil content, temperature and the change in pressure which causes the disruption of thermodynamic balance between viscous organic material like wax and asphaltine resulting in the formation of these materials with different mechanisms and their precipitation by moving through the formation's porous medium or in the tubing inside the production well or surface level facilities which removing them sometimes can be impossible and sometimes with great financial costs. According to what was said above, identification of the problem, flow condition and predicting the formation of these precipitations is very effective in the success of long term production operations and also the flow stability and economical production. So in the current state of Iran's wells and reservoirs, this is very important and essential that we pay attention to preventing the formation of asphaltine precipitation as well as reducing the viscosity when using enhanced oil recovery on reservoirs containing viscous oil with asphaltine. And it seems that with the addition of nano-particles to these type of oils we can increase the efficiency remarkably. In this article we will discuss the effect of Nano-particles on viscosity and precipitation starting point of the oil with asphaltine. For performing the required test, we proceeded toward building a rolling viscometer reader which has the capability of performing tests in a pressure of 7000 psi and a temperature of 95 oC. To compare the effects of different Nano-particles, six Nano-particles including TiO2, NiO, Fe3O4, Co3O4, Al2O3 and Co2O3 were used, to test the reduction of viscosity the wt% of 0.01 – 0.03 – 0.05 – 0.08 – 0.1 were used, and to test of the effect on precipitation Onset point of asphaltine for each Nano-particle the wt% of 0.01 was used. The results show that each specific type of Nano-particle has a specific performance and in a specific wt% has shown best performance in the reduction of viscosity, which in the viscosity reduction part respectively the Nano-particles of TiO2>NiO>Al2O3>Co3O4>Co2O3>Fe3O4 had the best performance and induced the most reduction amount. And also in the field of precipitation starting point the Nano-particles of TiO2>NiO>Fe3O4>Co3O4=Al2O3>Co2O3 had shown the best performance in delaying the precipitation starting point of asphaltine.