A　vector　acoustics　method　is　developed　to　investigate　noise　radiated　from　the　rotating　sources,　where　both　the　acoustic　pressure　and　acoustic　particle　velocity　are　computed　with　the　frequency-domain　numerical　method.　The　advantage　of　the　proposed　method　is　to　directly　display　the　acoustic　energy　propagation.　The　acoustic　energy　propagation　features　of　the　rotating　source　radiated　in　the　free　space　and　scattered　by　the　surface　are　analyzed　based　on　the　present　method.　©　2015,　Science　Press.　All　right　reserved.