The invention relates to a method and system for authenticating software. One embodiment of the invention provides a system for authenticating software in a mobile terminal, wherein the system is configured to: receive an execution instruction for software installed in the mobile terminal through an inputting means, generate a first error code for the software, extract a mobile terminal identifier of the mobile terminal, generate a first authentication key by combining the mobile terminal identifier and the first error code, and execute the software when the first authentication key corresponds to a second authentication key stored in the mobile terminal. By authenticating the software for a wireless mobile terminal, one embodiment of the invention can prevent unauthorized duplication and execution of the software at the mobile terminal.