The interaction of laser light with the transparent organic high polymers withQ‐switching dye was investigated. Several sorts of polyalkylmethacrylate plates, for which glass transition temperature was a function of composition of copolymers made of methylmethacrylate andn‐butylmethacrylate, were prepared, and the relationship between the growth rate of the laser‐induced damage and the thermal properties was examined. When the ambient temperature of these copolymer plates was 27°C, the growth rate of the damage becomes slower with the decrement of their glass transition temperature. The authors found that the difference (Tg‐T) or the ratio (Tg/T) of glass transition temperature (Tg) and ambient temperature (T) of the organic high polymers exerts predominant influence on the growth rate of laser‐induced damage.