The novel rich heteroatom-containing (15 wt %) composite molecular sieves M-1-MFI/M-2-MCM-41 have been prepared from the ionic complex [(C4H9)(4)N](2)(+)[M-1(EDTA)](2-) and [C16H33(CH3)(3)N](2)(+)[M-2(EDTA)](2-) as the organic templates, which could effectively introduce a large amount of heteroatoms into the framework of molecular sieves The products were characterized by XRD, XRF, SEM, HRTEM, N-2 adsorption-desorption, H-2-TPR, FT-IR. TG and DSC techniques. The catalytic performances of the composite materials were investigated by means of residual oil hydrocracking Characterization results showed that the composite materials simultaneously possessed a typical orthogonal MFI phase and a hexagonal MCM-41 phase and the two phases were composite rather than the physical mixture H-2-TPR data indicated all of the heteroatoms were incorporated by isomorphous substitution of silicon in framework N-2 adsorption-desorption analysis exhibited that these samples possessed regular and stable structure with high specific surface area and large pore diameters of 550-620 m(2) g(-1), 35 nm and 55 nm, respectively M-1-MFI/M-2-MCM-41 presented excellent activities in hydrocracking of residual oil, which were superior to the pure materials of MFI/MCM-41 (C) 2010 Elsevier Inc All rights reserved