According to ADA theory and Kramers-Kronig relationship, the real and imaginary parts of complex refractive index were estimated by the datasets of microcystis aeruginosa algal absorption and particle size distribution. Then, the optical properties of microcystis aeruginosa were calculated based on the Mie theory. The relative deviations between modeled and measured scattering efficiency factors are 10.08%, and 4.8% between absorption efficiency factors. The agreements between simulation result and actual measurement show that homogenous spherical model can be used to reproduce the absorption and scattering property of microcystis aeruginosa.