Si-MCM-41 with highly ordered hexagonal pore arrangement was synthesized hydrothermally at 100°C. The calcined Si-MCM-41 was then modified with Tetraethylenepentamine (TEPA) using impregnation method. By impregnation method calcined Si-MCM-41 was modified with 10, 20, 30, 40 and 50 (w/w) of Tetraethylenpentamine (TEPA). The physicochemical properties were studied by characterizing these samples with FTIR, TGA, XRD, and CHNS analysis. Results showed that Si-MCM-41 successfully modified with TEPA by impregnation method. FTIR results showed that all the characteristic peaks of Si-MCM-41 i.e. 794, 1080 and 1230 cm-1 were existed after modification which means that mesoporous frame work remain intact. TGA analysis showed that TEPA impregnated Si-MCM-41 samples have thermal stability in the range of 140-500°C. XRD results showed that intensity of the peaks reduced as the Si-MCM-41 modified with TEPA, this showed that TEPA molecules attached in the pores and on the surface. CHNS analysis confirmed the presence of carbon and nitrogen in the modified samples due to presence of Tetraethylenepentamine. © 2012 American Institute of Physics.