Algal Organic Matter (AOM) is derived from dissolved organic matter composition of the algal species observed. In this study, excitation-emission fluorescence spectroscopy has been used to determine the AOM and pigment characteristics of Chlorella sp. in varying algal biomass concentrations. The AOM and pigment characteristics were observed at 400-600 nm and 600-800 nm fluorescence emission, respectively with excitation spectrum of 300-450 nm. F680/450 is computed based on the ratio between the chlorophyll-a at 680 nm and dissolve organic matter contribution at 450 nm. F680/450 showed positive correlation with algal biomass (R² = 94.45), estimated chlorophyll-a pigment (R² = 87.12) of Chlorella sp. This study is a good reference for algal growth monitoring in biomass estimation and production in natural waters.