Mixing of poly(L-lactic acid) (PLLA) and poly(D-lactic acid) (PDLA) affords stereocomplex-type PLA (sc-PLA) having a high melting temperature of 230C, and its use provides higher thermal properties for PLA materials. The stereocomplex formation, however, is always accompanied by homochiral crystallization of PLLA and PDLA, causing deterioration of properties, when their molecular weight is higher than 100 kDa. Therefore, stereoblock-type PLAs (sb-PLA) consisting of PLLA and PDLA stereosequences are developed by utilizing new synthetic methodologies. The sb-PLAs exclusively generate the stereocomplex because of the better mixing state of their enantiomeric sequences and can be utilized as high-performance bio-based materials.