Objective To develop a steady-state mathematical model for oxygen concentration profile in perfusion bioreactor and a cardiac tissue construct as a function of flow rate and cell density. Method The cardiac tissue construct was cultured in perfusion bioreactor using scaffold with parallel channel array. The mathematical model was solved by computational fluid dynamics (CFD) commercial software to investigate the effects of cell densities and flow rate on oxygen concentration profiles in the construct. Result The simulation results indicated that the parallel channel array could mimic the role of the capillary network to enhance mass transport and improve the oxygen distribution partially in the scaffold. Oxygen concentration could increase with the medium flow rate, which was enough for low cell density in construct. However, this method couldn't provide enough oxygen for high cell density due to the less number and simple formation of the channel. Conclusions The mathematical model could be used to optimize scaffold geometry and flow condition for constructing cardiac tissue in perfusion bioreactor.