In　order　to　control　the　speech　level　automatically　in　the　3G　mobile　networks　where　Transcoder　Free　Operation　(TrFO)　is　adopted,　a　compressed　domain　automatic　level　control　(ALC)　method　is　proposed　based　on　ITU-T　G.722.2　speech　codec.　The　level　of　decoded　speech　is　first　measured　by　P.　56　tool.　Then,　based　on　the　difference　between　the　measured　level　and　the　target　level,　the　gain　of　ALC　is　calculated.　Finally,　the　codebook　gain　parameters　of　speech　codec　are　modified　according　to　the　ALC　gain　and　the　level　of　decoded　speech　is　adjusted　to　the　target　level.　The　result　of　performance　evaluation　shows　that,　in　comparison　with　the　traditional　method,　in　which　the　speech　signal　is　first　decoded,　then　level　adjusted　by　ITU-T　P.　56　tool,　and　finally　reencoded,　the　proposed　method　saves　65%　to　75%　of　the　computational　complexity.　The　difference　between　the　output　level　and　the　target　level　is　smaller　and　the　objective　speech　quality　is　much　better.　©　2012　IEEE.