Asphaltene precipitation and deposition problems are one of the severe problems which some reservoirs may face with them during their production life. Asphaltene deposition can affect on reservoir performance such as porosity and permeability reduction, wettability alteration, moreover it may lead to plugging of wellbore and production surface facilities. These effects can be modeled by consideration some asphaltene control parameters by activation asphaltene option in compositional simulation package. These parameters are usually estimated from core flooding experiments. This paper mentions the concept of asphaltene modeling and its related parameters and also describes the numerical study results of the effect of asphaltene precipitation and deposition control parameters on reservoir performance, by using a compositional simulation model with asphaltene modeling options. For this purpose, the real reservoir geology model and fluid data are used. After tuning the equation of state (EOS) by analyzing the oil properties data and setting the asphaltene control parameters, the simulation model is built by incorporation of the EOS for asphaltic oil properties and the asphaltene parameters into the compositional simulation model. The model enables the simulation of asphaltene precipitation, flocculation, and deposition including adsorption, plugging, and entrainment. Also, it can show the resulting reduction in porosity and permeability and changes in oil viscosity and rock wettability according some range of asphaltene control parameters. The model is used to investigate the effects of these parameters selection on reservoir performance, including oil production, recovery factor and average reservoir pressure, also, asphaltene behavior including precipitation, flocculation, adsorption, plugging and entrainment, moreover, formation damage and its effect of rock wettablity changes. The results show the effect of the asphaltene precipitation and deposition parameters selection on reservoir performance clearly, so it should correctly calibrate and carefully use them for modeling. Also, for reservoir that does not have any asphaltene core flooding experiment, they will be useful for estimating the asphaltene model input parameters and its effect on simulation results. Copyright 2011, Society of Petroleum Engineers.