Polylactide (PLA)/bamboo fiber biocomposites treated with an alkali solution and a silane coupling agent were prepared by melt compounding. The PLA composite containing delignified bamboo fibers showed a narrow decomposition range of $300-400^{circ}C$ compared to the PLA composite containing pristine bamboo fiber ($210-430^{circ}C$). The tensile and flexural moduli of the treated PLA/bamboo tiber composite increased with increasing bamboo fiber content. The tensile and flexural moduli of a PLA/bamboo fiber composite treated with an alkali solution was higher than that of a PLA/bamboo tiber composite containing pristine ban1boo fibers. The PLA/bamboo fiber biocomposites treated with an alkali solution and a silane coupling agent exhibited higher tensile and flexural strength than a PLA composite containing pristine bamboo fibers, and the tensile strength was twice that of the PLA composite containing untreated bamboo fibers. This enhancement in the mechanical properties was attributed to surface modification and improvement of the interfacial adhesion between the PLA matrix and bamboo fibers.