In free space optical communication, the transmission characteristics through atmospheric channel have important effect on system performance, for example, atmospheric turbulence can cause fluctuations in both the intensity and the phase of the received light signal. The existing system mostly uses intensity modulation and direct detection(IM/DD) because of low complexity and cost, despite atmospheric turbulence can significantly impair link performance and induce a string of error bits. In order to mitigate turbulence effect, coding techniques can be adopted. For a long string of error induced by turbulence units, interlaced code changes the abrupt error into absolute error, thus it can be easily corrected. We analyze the impact of interlaced code on the performance of FSO system whose signal passes through the turbulent atmosphere. Simulations are presented to verify the performance improvement achieved using coding for free space optical communication through atmospheric turbulence channel.