Laser oscillation from dye-doped microparticles of organic polymers was investigated. Spectral shift in peak wavelengths of laser oscillation depending on pumping intensity was observed in the microparticles of poly(cyclohexylmethylsilane) (PCHMSi). The shift observed for PCHMSi microparticles was discussed in terms of the third-order non-linear optical (NLO) effect. It was concluded that the effective power density of light just inside the microparticle's surface was about 30 times larger than that of the pump pulse.