Various light intensity and light quality were treated to oat seedlings to investigate the effect of light on the chlorophyll accumulation and the formation of chlorophyll-protein complexes. The increase of total chlorophyll accumulation and Chl (chlorophyll) a/b ratio was promoted under H (high intensity) white light during oat chloroplast development when compared to L (low intensity) white light. Also H white right was more effective in the formation of chlorophyll-protein complexes associated with PSI, CCI and CCII than L white light. The seedlings grown in various light quality caused little changes in total chlorophyll and Chl a/b ratio when compared to those grown in L white light. The assembly of LHCII trimer was more affected by L white light treatment in the formation of-chlorophyll-protein complexes than red light treatment. The effect of blue light on the relative composition of chlorophyll-protein complexes was similar to that of L white light. Particualrly, blue light was more effective in the synthesis of LHCII monomer than the other hot quality at the early stage of greening. When compared to red light, blue light was more effective in the formation of LHCII monomer. These results suggest that light intensity is more effective in the increase of chlorophyll accumulation and Chl a/b ratio than light quality, and light quality may be an important factor for the regulation of the organization in the chlorophyll-protein complexes during greening.