An anti-“Methicillin-Resistant Staphylococcus Aureus (MRSA)” chitosan containing antibacterial High Wet Modulus (HWM) rayon fiber textile for medical usage is made of the steps as following: chitin flakes made from natural shrimp or crab shells are deacetylated to generate chitosan with a high deacetylation degree of 90% or more. Next chitosan is dissolved in acetic acid and regenerated by caustic soda to form a chitosan antibacterial nanoparticles slurry, then added to HWM viscose rayon process, and spinning to produce a chitosan containing antibacterial HWM rayon fiber. The antibacterial amino groups of chitosan and the hydroxyl groups of rayon cellulose combine together via hydrogen bonding. Therefore, the fiber becomes the anti-MRSA antibacterial HWM rayon fiber containing amino groups (—NH3+). Finally the resulting HWM rayon fiber is conducted via a yarn spinning or/and weaving process to procure a medical textile with chitosan content.