6-(Alkyloxyphenyl)carbonyl substituted spirobenzopyran (COSP) was synthesized from 6-(hydroxyphenylcarbonyl)substituted salicylaldehyde and indoline, followed by alkylhydroxylation with 6-chloro-1-hexanol. Resulting COSP was modified to a methacryloyl substituted COSP derivative, which was polymerized with styrene (ST) and butylmethacrylate (BMA) to give a terpolymer of COSP-ST-BMA (PCOSP). COSP monomers and PCOSP were thermally more stable than 6-nitrospirobenzopyran. Fast photochromic coloration was observed from a COSP doped polymer or PCOSP film upon irradiation with a light of 340 nm.