The present invention discloses a multi-code Chien's search circuit for BCH codes with various values of m in GF(2m). The circuit includes: a combined matrix unit, a number of first multiplexers, a number of registers and a number of second multiplexers. By designing the Chien's search circuit having several Chien's search matrices, with peripheral components, it is able to achieve applications for different code rates, different code lengths and even different m in GF(2m).