Preferentially oriented Ag crystals with platy surface morphology were prepared under appropriate Langmuir monolayers by using electrodeposition plating method at a small current. On the other hand, randomly oriented Ag crystals with needle-like morphology grew at the air/subphase interface in the absence of a monolayer, or under a monolayer at a relative large current. It was noted that two dimensionally oriented Langmuir monolayers promote the two dimensional crystallization of metallic crystals through chemical interactions at inorganic-organic interfaces.