In　order　to　represent　the　optical　scattering　properties　of　the　complex　surfaces,　a　semi-empirical　model　for　bidirectional　reflectance　distribution　function(BRDF)　based　on　micro-facet　theory　was　proposed,　with　which　optical　scattering　properties　of　a　certain　kind　of　material　are　decided　by　parameters.　In　order　to　prove　the　model,　the　experiment　system　to　measure　the　bidirectional　reflectance　distribution　function　has　been　designed,　where　a　905nm　pulsed　laser　diode　is　used　as　the　light　resources,　a　PIN　photodetector　is　used　to　measure　the　echo　signal,　and　the　reflection　from　an　aluminum　sample　is　measured.　For　the　complex　nonlinear　relationship　between　the　experiment　data　and　modeling　parameters,　genetic　algorithm　was　used　to　retrieve　the　model　parameters.　The　results　prove　that　calculation　of　the　model　complies　with　experiment　data.　It　can　be　used　as　a　reference　for　target　feature　extraction　and　recognition　in　the　future.　©　2011　IEEE.