Bacteria normally live in closed communities called biofilms. Living within a biofilm can be beneficial for the bacteria. It can protect them from harmful environ- mental conditions and from toxic substrates such as antibiotics. Within the biofilm, identical cells perform different tasks ranging from building extracellular matrix to forming spore cells. These tasks can be performed and processed by complex gene regulation networks. The formation of biofilm is governed by a complex gene reg- ulation network. In this thesis, we examine the interaction of three proteins: SinI, SinR and SlrR which govern biofilm formation in Bacillus subtilis. In the analysis, we use deterministic and stochastic mathematical models, bifurcation analysis and numerical simulations for a better understanding of the biofilm formation process. Our results reveal that SlrR locks the system into the matrix producing state by repressing SinR leading to the initiation of biofilm.