The structural and magnetic properties of Zn-substituted Li-Cu ferrites having the general formula LixCu0.4Zn0.6-2xFe2+xO4 (where x=0.0, 0.05, 0.1, 0.15, 0.2, 0.25 and 0.3) were investigated as a function of Zn content. The X-ray analysis confirmed the single phase formation of the samples. The lattice parameter increases linearly with Zn content, which is attributed to ionic size differences of the cations involved. The bond lengths R-A and R-B are found to increase with increase in Zn content. The increase of R-A and R-B is attributed to the increase in lattice parameter. The magnetic moment increases with increase in zinc content up to x=0.3 and then it decreases with further addition of Zn. The decrease in magnetic moment beyond Zn=0.3 is due to the presence of a triangular spin arrangement on B-site; the three sublattice model suggested by Yafet and Kittle.