Abstract: This paper begins with a breif description of fundamental theory of Statistical Energy Analysis (SEA). According to the model of SEA, the calculation of sound insulation of partitions, single wall, double wall and double panels connected with studs, is transformed into solying a systems of linear equations. The evaluation of coefficients of the equations, namely the parameters of SEA, is discussed. Gypsum board walls are used as object of study. Radiation resistance, loss factor and sound transmission loss are measured. Sound insulation of seventeen types of gypsum board walls are calculated by a computer. Agreement between calculated results and experiments is found to be good. Finally, the effect of some factors on sound insultion of walls is discussed.