Effect of crystallinity change on electrical conduction characteristics of poly-L-lactic acid was studied experimentally. The crystallinity was changed by thermal annealing. The lower crystallinity samples have more remaining charge than the higher crystallinity samples. Moreover, at 80 °C that is above their glass transition temperatures (Tg: 55-60 °C), the conductivity is much higher in the lower crystallinity sample than in the higher crystallinity sample. The low crystallinity sample shows two thermally stimulated current (TSC) peaks - one around Tg and the other at a temperature about 20 °C higher than Tg, while the higher crystallinity sample shows only the lower-temperature TSC peak. The TSC peak around Tg is attributable to the micro-Brownian motion that enables orientation of dipoles having the direction perpendicular to the polymer main chains, while the higher-temperature TSC peak seems attributable to the orientation and magnitude change of the end-to-end vector in the polymer main chain.