PLLA/PBSL(PBS) blends with PLLA content not less than 60 wt%, and phase inversion occurs for the corresponding 40/60–20/80 blends. As a whole, the dispersed phase was finely and homogeneously dispersed in the matrix for the blends with a low content of the dispersed component. The approximate diameters of the dispersed PBSL(PBS) phase were 0.1–0.4 μm at the PBSL(PBS) contents 5–20 wt%. The dispersed PLLA phase had a similar size for the blends with the PLLA content 20 wt%.