The interaction between the two convective systems separated by free lateral boundaries and the pattern formation have been studied. We have prepared a cell, where two identical convective subsystems with small aspect ratios are placed in the direction of the roll axis and coupled through the free lateral boundaries and the liquid crystal placed in-between. It is found that the evolution of convection in one subsystem is affected by the state of the other subsystem through the free boundaries. Moreover, the entrainment of the spatial pattern is observed.