Raman　spectra　of　crystal-octadecyl　hydrogen　succinate　(OHS),　whose　geometric　disposition　of　the　experiment　has　ȳ　(zx)　y,　ȳ　(zz)　y,　and　ȳ　(xz)　y,　ȳ　(xx)　y　respectively,　have　been　recorded　and　analyzed　with　the　purpose　of　understanding　the　structure　of　OHS　crystal.　It　shows　that　some　of　the　Raman-active　modes　of　alkyl　chain　appear　polarization.　The　analysis　for　crystal　structure　indicates　that　the　molecular　of　OHS　arrange　in　layers　along　[100]　and　[001]　by　the　mode　of　dimers,　and　the　molecular　layers　of　chain　pile　up　along　[010].　The　other　groups　of　OHS　corresponding　Raman　vibration　peaks　have　been　analysized　as　well.