Abstract: The present invention relates to the humanized antibodies to surface antigen S of hepatitis B virus and a preparing method thereof. Particularly, it relates to the humanized antibodies which comprise heavy and light chains having amino acid sequences originated from human antibodies at the HCDR1, HCDR2, HCDR3 and LCDR1, LCDR2, LCDR3 of their variable regions, expression vectors containing each of the heavy and light chain genes of the humanized antibody and transformant which can produce humanized antibody by transfection with heavy and light chain expression vectors and a preparing method thereof. A humanized antibody of the present invention is more humanized than that of the previous arts. So, it minimizes the probability of immune response in humans and has good antigen binding capacity, making it a excellent candidate for prevention and treatment of the hepatitis B virus infection.