A new unsymmetrical photochromic diarylethene namly 1-(2,4-dimethyl-5- thiazolyl)-2- [(2-methyl-5-(2-pyridyl)-3-thienyl)]perfluorocyclopentene was synthesized, and its photochromic and fluorescent properties were also investigated. The compound exhibited good photochromism both in solution and in PMMA film. In PMMA film, The open-ring isomer of the diarylethene 1 exhibited relatively strong fluorescence at 427 nm when excited at 320 nm. The fluorescence intensity declined along with the photochromism upon irradiation with 297 nm light. Using this dithienylethene 1b as optical storage was performed successfully.