•Bamboo advantages including growing fast, strong mechanical properties, and low-cost.•Plantation, harvesting and processing of bamboo has global socio-economic benefits.•The increase in the alkali concentration reduces wax, ash contents, and cellulose.•There is an optimum NaOH concentration level, immersion time, and temperature level.•Excessive alkali concentration damaged the fibers and affects the mechanical properties. Applying bamboo fibers into the composite reinforced concrete governs some significant drawbacks, including inadequate adhesion between fiber and matrix interface, and hydrophilic nature. Thus, the mercerization of bamboo fibers is suggested to overcome these limitations. In this review, the thermal and mechanical properties of alkalized bamboo fibers have been evaluated. It was concluded that alkalization treatment of bamboo fibers could provide enhanced bio-composites properties up to a great extent. Besides, the betterment of the thermal stability and mechanical properties of the alkalized bamboo fibers and its composite depends closely on the temperature level, immersion time, and NaOH concentration percentage.