NEW MATERIAL:A fluorine-containing amide compound expressed by formula I (R1 and R2 are H or 1-30C alkyl which may have a branched chain). EXAMPLE:A compound expressed by formula II. USE:Useful especially as a surface modifier for high polymers and also as a sliding agent for surfaces in contact with metal and further as a metal surface treating agent, water and oil repellent, etc. PREPARATION:A benzenemonocarboxylic acid or benzenedicarboxylic acid having perfluorononeyloxy group as a starting raw material is reacted with thionyl chloride, etc., and converted into an acid chloride, which is then reacted and amidated with various amines in the presence of a base, such as triethylamine, in a solvent, such as diethyl ether, to afford the compound expressed by formula I.