This study aims to find out how the effect of addition and time of soaking of the bark fibers of the tree on bending and impact strength. The effect of the alkalization time for 60 minutes, 90 minutes and 120 minutes with fiber volume fraction of 20%, 30%, and 40% in the composite composite of applied bark fiber on the amount of absorbent energy and impact price increased the amount of fiber volume fraction in composite specimens impact will increase the value of the impact resilience itself and the longer the immersion time will make the value of impact toughness decreases, this is because the longer the alkalization time will affect the physical and mechanical properties of the fiber, where natural fibers will become stiffer and toughness values the impact decreases. and the effect of alkalinization time of 60 minutes, 90 minutes and 120 minutes with fiber volume fraction of 20%, 30%, and 40% on the composite composite of applied tree skin fibers to the maximum load and bending stress, obtained the increasing number of fractions of fiber volume adding value from the bending strength itself, while the longer the immersion time will cause the strength of the bending value to decrease, this is due to the longer immersion time can affect the physical and mechanical properties of the fiber, where natural fibers will become stiffer and the bending stress decreases.