1,3,5,-Trimethyl-1,1,3,5,5-pentaphenyltrisiloga,ne has been prepared by the equilibration of 1,3-dimethyl-1,1,3,3,-tetraphenyldisilosane and methylptienyloy-closiloaanes in the presence of tetramethyl ammonimn silanolate.By the repeated recycling of the by-products siloxanes,it wag possible to obtain an overall yield of over 90%.The physical properties and the oxidative stability of 1,3,5-trimethyl 1,1,3,5,5-pentaphenyltrisiloxane were also determined.