A series of dually mixed self-assembled monolayers were prepared by a simple step-by-step method. Four carbonyl chlorides with different chain lengths were selected and assembled onto a N-[3-(trimethoxylsilyl)propyl] ethylene diamine self-assembled monolayer. Different mixed films were obtained by controlling the ratio of co-deposited carbonyl chlorides. The structures of the films were characterized by measuring their contact angles, ellipsometric thickness, and atomic force microscopy. No phase separation was observed in the mixed films. Micro-tribological studies were also carried out on the films. It was found that frictional coefficients decreased as the ratio of the longer component was increased.