Protocol translation is a method for transforming pieces of information from a source protocol into relevant target protocol formats in order to communicate between heterogeneous legacy systems in interoperability environments. There are some existing protocol translation technologies for network protocols and simple data messages, but these have semantic information problems such as information distortion or incorrect information translations when applied to semantic messages. To deal with these problems, I propose a method that translates messages to semantically equivalent messages. I devised the method to be practical in implementing semantic information-sensitive gateway systems. I conducted a comparative experiment with the translation approach developed in the defense domain. I found that my semantic translation method provides more accurate and efficient message translations in interoperability environments.