Many researchers used some models based on the assumption of spherical in shape particles. Particles shape is important and should be considered in models. In this work, a new model was used for prediction of gas permeability through the Mixed Matrix Membranes (MMMs). The effects of particles shape and undesirable defects (polymer chain rigidification, partial pore blockage and void formation) were introduced to the model simultaneously. The model was employed to predict some experimental data. The results showed that the less average absolute relative error (AARE) of the model for the MMMs were about 0.73-31.53%.