In order to collect and evaluate the wild germplasm resource for Sesuvium portulacastrum（L.） L. in the Hainan Island，we conducted five times of sample investigation in the coastal areas around the Hainan Island through eastern and western lines. Sixteen wild populations of S. portulacastrum（L.） L. were found from 11 cities or counties. We further collected information of the geographical distribution，growth environment，and associated plants for these S. portulacastrum（L.） L. germplasms. By analyzing their distribution characteristics， we found that S. portulacastrum（L.） L. was mainly distributed in beach and coastal areas with an average elevation about 7.4 m，ranging from north latitude 18°14′-20°05′ N to east longitude 108°39′-110°59′ E. 27 associated plants for S. portulacastrum（L.） L. were observed. We further analyzed the morphological and physiological characteristics of these plants under different salt conditions，followed by the principal component analysis to evaluate their salt tolerance ability. The wild germplasms collecting from Jiangnancheng in Haikou City and Qinglan Port of Wenchang City showed higher salt tolerance，whereas the samples from Yangpu Xinyingwan in Danzhou City and Yanjin Village in Lingshui Li Autonomous County were more salt-sensitive. Altogether，this study achieved a systematic investigation of the wild S. portulacastrum（L.） L. germplasm resource in Hainan Island，and found several wild germplasm resource which served as valuable materials to unlock the molecular mechanism for salt tolerance in S. portulacastrum （L.） L..