This　letter　proposes　an　extended　image-source　model　to　simulate　the　room　transfer　function　for　a　rotatable　complex　source　in　a　three-dimensional　reverberant　room.　The　proposed　model　uses　spherical　harmonic　decomposition　to　describe　the　exterior　sound　field　from　the　complex　source.　Based　on　＂axis　flip＂　concept,　the　mirroring　relations　between　the　source　and　images　are　summarized　by　a　unified　mirroring　operator　that　occurs　on　the　soundfield　coefficients.　The　rotation　movement　of　the　source　is　taken　into　account　by　exploiting　the　rotation　property　of　spherical　harmonics.　The　accuracy　of　our　proposed　model　is　verified　through　the　appropriate　simulation　examples.