Performance of 27 MLD Plant for wastewater treatment (WWTP) by Sequential Batch reactor was studied over a period of three months. Results showed that Chemical Oxygen Demand (COD), Biochemical Oxygen Demand (BOD) and Total Suspended Solids (TSS) decreased through stages of the treatment process. The percentage removal of these parameters during studied period ranged 91.10 to 95.24%, 86.21 to 94.25%, and 92.36 to 96.60% respectively. The sequencing batch reactor (SBR) is a modification of activated sludge process which has been successfully used to treat municipal and industrial wastewater. In this work, an attempt has been made to carry out the performance evaluation of 27 MLD SewageTreatment Plant with Sequential Batch Reactor process at Haridwar. For this purpose performance data were collected from sewage treatment plant and were analyzed in terms of BOD, COD and TSS removal efficiency. It is formed that SBRs processes are working satisfactory.