Poly(butylene adipate) (PBA), a biodegradable linear aliphatic polyester, can be potentially applied as the biomedical and eco-friendly materials. In this study, the Mg-Al layered double hydroxides (LDH) prepared using one-step coprecipitation method were successfully synthesized by intercalating the oleate into the interlayer spacing of LDH (assigned as OLDH).Wide-angle X-ray diffraction data showed the interlayer spacing increased from 0.83nm of LDH into 3.4nm of OLDH with the addition of oleate. The surface property of LDH was changed from hydrophilic to hydrophobic characteristic. The PBA/OLDH nanocomposites were prepared via a solution mixing process. The isothermal crystallization rate obtained using differential scanning calorimetry has been decreased apparently with the addition of OLDH, which acts as a nucleating agent for the crystallization of PBA. The addition of OLDH decreased the crystallization half-life time (t1/2) from 6.31 min of neat PBA to 19.1 min of 0.5 wt% PBA/OLDH. The polymorphism and ring-banded spherulites determined using x-ray diffraction and polarized optical microscopy were also studied.