A plasma generator, a surface treatment method using the same, and a surface treatment method using the same for bio-tissue are provided. The plasma generator comprises a plasma tube, a reaction source tube, a first electrode and a second electrode. The plasma tube has a plasma outlet. The reaction source tube is disposed within the plasma tube, and has a reaction outlet. The first electrode and the second electrode are disposed on the plasma tube, wherein the second electrode is closer to the plasma outlet than the first electrode is. The plasma outlet of the reaction source is not projected beyond a lower portion of the first electrode.
