In the present work, our investigation is to study the optical and thermal properties of the binary mixture of cholesteric and nematic compounds namely, decyloxy benzoic acid (DBA), and cholesteryl chloride (ChCl), which exhibits different liquid crystalline phases with reentrant smectic-A phase. The reentrant smectic-A phase has been observed at different concentrations and at different temperatures. The existence of reentrant smectic-A phase has been observed by optical microscopic studies. The temperature variation of optical anisotropy, X-ray and helical pitch of the cholesteric (N-*) phase has also been discussed.