In the last decade, studies have focused on identifying microalgal species responsible for wastewater treatment in high rate algal pond (HRAP). In this study, investigation of the microalgal community composition in Pilot-scale Race way-type high rate algal pond through study period of 24 months, chlorophyll “a" content was estimated, Physico-chemical parameters were analyzed, light intensity and temperature also measured, and the biomass productivity was calculated. It was found from the recorded results that, more than 19 genera of phytoplankton belonging to 4 divisions were identified with dominance variation throughout the study period. The presence of the species inside the pond is dependent on seasonal variation. Chemical analysis data exhibit a significant increase of COD, BOD, and TSS concentration with the temperature increase. There is an obvious impact of light intensity and temperature on the growth rate, where the highest growth response of 3.5 mg/l Chl. (a) was achieved at the highest light intensity of 1900 lux with a temperature degree of 39 °C. The average algal biomass produced from HRAP 0.99 kg algae/m3/d. This study demonstrates that the predominance of algal community structure affected by seasonal variations, and there are clear light intensity and temperature impact on the growth rate, as well as there was a promising production of algal biomass can be used in different aspects.