The effect of chitosan treatment on the dyeing and dye fastness, and mechanical properties of hair was investigated in this study when the carotinoid dyestuffs extracted from African Marigold(Tagetes erecta L.) were applied to the hair. The sequences of the chitosan treatment were changed in dyeing and mordanting procedures, i.e., pre-treatment, mid-treatment, and post-treatment. While the effect of chitosan application on the color shade change was not significant, the pre-treatment of the chitosan increased the dye uptake. Discoloration and fading was observed in the lightfastness test when chitosan was mid-treated. Alkali perspiration and acid perspiration fastness test results showed that chitosan post-treatment gave lower tendency. Washing fastness results showed that chitosan post-treatment and mid-treatment gave lower values, which indicates that chitosan deters the direct formation of insoluble complex among fiber-dyestuff-mordant. In the mechanical characteristics results, however, initial modulus and breaking strength increased significantly in the post-treatment and pre-treatment of chitosan.