In this paper, we report our theoretical study on the influence of black matrix (BM) on the optical performance of liquid crystal cell as a light valve. For our numerical simulation, a couple of widely employed electrode patterns-PVA (Patterned Vertical Alignment) and the Super IPS (In-plane Switching) cells, were chosen for our theoretical investigation on the dependence of BM on the transmittance and capacitances. In addition, a careful comparative study was also undertaken between the case when high-permittivity dielectric is employed and the other case when a floating metal is used for BM. Our simulations revealed that the Super IPS mode is more sensitive to the insertion of BM than the PVA mode cell. It also turned out that the influence of parasitic capacitance is more appreciable in case when high-permittivity dielectric is chosen for BM than the case when a floating metal is employed for BM.