Thermal properties and phase behavior of series of main chain copolymers containing oligomeric-L-LA segments (OLLA) and biphenol groups were synthesized and characterized. OLLA segments were prepared by ring opening polymerization of L-LA initiated by biphenol mesogens with active HO-group and then polymerized to form main chain polymer by the reaction pentanedioyl dichloride with the-OH groups at the free end of OLLA. Their phase behaviors were studied by using DSC and POM. XRD measurements revealed the formation of layered structures. CD measurements were used to measure the helical structure and the optical rotation power of the main chain polymers.