Langmuir-Blodgett monolayers were prepared using a series of aminimide derivatives having two alkyl chains. One of the alkyl chains had 19 carbons, while the number of the other alkyl chain was systematically changed from 8 to 20. Molecular organization of the aminimides on the water surface reflected the length of alkyl chains. Inter-chain packing and conformational order of the alkyl chains in the monolayer were affected by the length of the two alkyl chains. Steric and dynamic contact angles of a series of aprotic liquid having low surface tension were measured to investigate surface properties of the films with varying molecular organization of alkyl tail groups. Fluid-like monolayers having molecularly rough surface indicated high wettabilities for both of n-alkanes and naphthalene derivatives. However, contact angle hyteresis on the monolayer was sensitive to the sort of probe liquids owing to the interaction between the uppermost portion of the alkyl chains aligned homeotropically on the fluid-like monolayers. In contrast, the monolayer containing well-ordered, well-packed alkyl chains indicated low wettabilities, small hysteresis and random orientation of liquid crystals.