This paper deals with the modelling of substrate inhibition in microbial growth processes. For the successful applications and overall model validation in microbial growth processes, a new substrate inhibition model-modified Haldane model-has been developed. Performances are compared on the basis of different experimental data in the literature and, of parameter sensitivity analysis. Finally, the parameter sensitivity analysis emphasizes that the modified Haldane model has a very simple but flexible enough model structure for representing the microbial growth kinetics with limited number of parameters.