A mathematical model using the Weibull distribution that characterizes the fate of virus-infected insect cells to conduct viral replication and subsequent recombinant protein synthesis and finally to die due to the progress of viral infection is presented. This model also takes into account the degradation of synthesized protein due to intrinsic denaturation and/or proteolytic hydrolysis. Model parameters were determined from the literature and based on experimental data. The model agrees well with the experimental data from cultures under different infectious conditions. Model simulations of virus-infected insect cultures reveal the importance of the interaction of the cell density at time of infection and multiplicity of infection and the presence of the best time for harvesting.