Two monoarm liquid crystalline crown ethers and coordination complex (1, 2 and 1.Eu^3^+) were studied by the method of LB technique. They were spread on the air-water inter-face to form stable monolayers, which could not easily be transferred onto glass substrate. In addi-tion, compound 1 underwent a first-order phase transition during the compressing process. The molecular configurations and area in the films were estimated wich CPK model which agreed with the experimental results. The effect of molecular structures on the phase transition was briefly dis-cussed.

Key words: CROWN ETHER COMPOUNDS, PHASE TRANSFORMATION, FILM FORMING CHARACTERISTICS, LIQUID CRYSTALLINE POLYMER, CROWN ETHER, L-B MEMBRANE