. In general thermodynamics and colloidal models are used for Asphaltene modeling. In this work employed solid thermodynamic model for modeling and sensitive analysis on key parameters; such as solid molar volume and binary interaction between precipitating component and light fluid components. PVT data is used for modelling for an Iranian oil sample that experimental data includes CCE test, Differential Liberation test and saturation pressure. Current study is focused on finding the optimized characterization by examining several fluid properties correlations, equation of states, BIPs and distribution functions for the oil sample. In fact the aims are how much Asphaltene and under what conditions it would precipitate. The model do not show any precipitation in surface reservoir and facilities that one of its reason could be reversibility of Asphaltene precipitation in reservoir fluids. The model can not predict precipitation in pressure less of 3550 psia. According to modelling results, precipitation molar volume is 0.68 L/mol and its Carbon number is 36 ( ). PR 1978 EOS showed more agree with exprimental data between another EOS. Moreover Asphaltene precipitation molecular weight obtained 649.63 g/mol. Keywords: Asphaltene, Precipitation, Thermodynamic Solid modeling
