Some experiments for fundamental understanding of micro-phase separated structures formed in mixed monolayers ofn-alkyltrichlorosilanes and a partially fluorinated amphiphile are presented. The surface morphology of the mixed monolayers is varied by changing some parameters, such as chain length of alkyltrichlorosilanes, temperature of the water surface, and solvents of spreading solutions. It is demonstrated that the surface structures are mainly governed by the dynamic molecular process during spreading. The most likely mechanism of the micro-phase separation is proposed.