Poly(1,4-butylene adipate) (PBA), poly(L-lactic acid) (PLLA) and poly(D-lactic acid) (PDLA) belonged to biodegradable polymers and were friendly to environment. Thus, crystallization kinetics and morphology of PBA blended with of 1–5 wt% loadings of PLLA and PDLA stereocomplex crystallites (SC), as biodegradable nucleating agents, were studied using differential scanning calorimetry (DSC), polarizing optical microscopy (POM), and wide-angle X-ray diffraction (WAXD). The SC acted as nucleation sites could increase the crystallization rates of PBA estimated by half-time crystallization (t1/2). Upon the addition of 3% SC, the t1/2 of PBA/SC composite decreased about 46~63% under isothermal crystallization in the temperature of 38~44℃ as compared to that of neat PBA. With the presence of SC, the nuclei number of PBA increases and the spherulite size significantly reduces. The WAXD data showed that the crystalline structure of PBA remains unchanged when crystallized with the presence of the SC crystallites.