The East China Sea (ECS),one of the largest continental seas,has dynamic hydrology and complex optical characteristics that make ocean color remote-sensing retrieval difficult.The distributions and proportions of the light absorption coefficients of major ocean color components based on two large-scale investigations in the ECS are presented,showing these features in typical summer and winter seasons.The absorption coefficient a CDOM,a NAP and a phy of colored dissolved organic matter,non-algal particle,and pigment of phytoplankton show a decreasing trend from the coast to the outer shelf.According to the a CDOM distribution at 440 nm,the Changjiang River plume shows an abnormal southeastward transport.An extremely high a NAP value patch at 440 nm is present in the middle coast.The chlorophyll-a-specific phytoplankton pigment absorption (a phy) is much higher in winter than in summer,which may cause serious underestimated results when applying the averaged a phy into remote-sensing algorithms for chlorophyll concentration retrieval.The importance of phytoplankton size was evident in outer shelf waters.The absorption of a CDOM (440) is a dominant component accounting for over half of the total seawater absorption in summer.The a NAP (440) accounts for 64% of the absorption of the ECS coastal area in winter. The East China Sea (ECS), one of the largest continental seas, has dynamic hydrology and complex optical characteristics that make ocean color remote-sensing retrieval of the distributions and proportions of the light absorption coefficients of major ocean color components based on two large -scale investigations in the ECS are presented, showing these features in typical summer and winter seasons. The absorption coefficient a CDOM, a NAP and a phy of colored dissolved organic matter, non-algal particle, and pigment of phytoplankton show a decreasing trend from the coast to the outer shelf. According to the CDOM distribution at 440 nm, the Changjiang River plume shows an abnormal southeastward transport. An extremely high a NAP value patch at 440 nm is present in the middle coast. The chlorophyll-a-specific phytoplankton pigment absorption (a phy) is much higher in winter than in summer, which may cause serious underestimated results when applying the averaged a phy into remote-sensing alg orithms for chlorophyll concentration retrieval. The importance of phytoplankton size was evident in outer shelf waters. The absorption of a CDOM (440) is a dominant component accounting for over half of the total seawater absorption in summer. a NAC (440) accounts for 64% of the absorption of the ECS coastal area in winter.