In the present article, the general geometrical model is extended to estimate the excess molar volume in multicomponent systems. The model can overcome the inherent defects of the asymmetrical and symmetrical models, and more reasonable in the theoretical consideration and more reliable in the practical application. The integration process is avoided by applying the general relations between the "similarity coefficient" and the parameters of the binary R-K type polynomial, which greatly simplifys the calculation. The successful applications of the general geometrical model to four ternary systems show that it is possible to calculate the molar volume with this method. (C) 2009 Elsevier B.V. All rights reserved.