The aeration characteristics of perforated tray aerator were determined by conducting aeration experiments in a cement concrete tank of dimension 4m×4m×1.5m. The perforation diameter d: (2mm) and flow rate: Q (10L/s) were kept as as constant and experiments were conducted with varying number of perforated trays (n): 1, 2, 3 and 4. Optimum numbers of trays were found to be three. Further, the numbers of perforated trays were kept as constant, the perforation diameter and flow rate varied by the application of response surface methodology (RSM) and central composite rotatable design (CCRD) for optimisation of variables. The ranges of variables used in the design were d (1 to 5 mm) and Q (7 to 19 L/s) at an interval of 1 mm and 3 L/s respectively. In order to optimize standard oxygen transfer rate (SOTR) and standard aeration efficiency (SAE), mathematical models were developed using computer simulation by least squares method and Design-Expert software. The results of the study indicate that the SOTR and SAE were significantly affected by both the parameters (p<0.0001) at quadratic levels but no significant effect was observed at the interactions level.