Abstract: Tetraphenylphenyl triethoxysilane and its hydrolysate and pre polymer were synthesized. The stationary phase was obtained by (1) dissolving the hydrolysate or prepolymer in benzene and then coated on the diatomaceous supports, and (2) the coated support was heat-treated at 400℃ under a stream of nitrogen for 12 hours. The characteristics of the prepared column were, (l) A mixture of n-alkanes contaning C₇-C₃₀ has been well separated when the temperature was programmed to 320℃. (2) n-C₁₆H₃₄ could be dertermined quantitatively. (3)Maximum temperature of 320℃ has been used without bleeding. (4) The number of HETP was 700 plates per meter approximately.The effects of the surface properties of the supports, of the quantity of the hydrolysate or prepolymer used in preparing the stationary phase, and of the temperature and period of heat-treatment on thecharacteristics of the column are discussed.