Abstract: A method for designing complementary coded navigation signals on the basis of analyzing the Loran-C codes （Ref. 4 ） is presented in this paper. The method is described as follows: 1. Taking a pair of m-element complementary codes. 2. Concatenating the m-element codes to form a pair of 2m-element codes. 3. Interleaving the 2m-element codes to form a pair of 4m-element codes:A and B. 4. Taking A and B, or A and B, or Aand B,or A and B as the master station codes M and M". 5. Taking M" and M', or M" and M' as the slave station codes S' and S". By using such codes, automatic master and slave station search and identification, and multihop skywave rejection may be achieved easily in a time sharing multistation navigation system. The method is proven in detail. Examples of codes, including the Loran-C codes, are also given.