A spiropyran derivative introduced long alkyl chain (SP-18) was evaporated on a glass plate and a polystyrene cast film containing silica particles. SP-18 films indicated reversible photochromism by UV-irradiation and standing under the dark. Change of surface properties of SP-18 film by photochromism was discussed based on wettability. Change of contact angle of water by photochromism was 35degrees in maximum.