Abstract:Two new atyid shrimps, Caridina wangan Hou, Zhang, Guo sp. nov. and Caridina lineatus Hou, Zhang, Guo sp. nov. are observed from the streams of the Longgun River in Beida Town,Wanning City. The endopod of the first pleopod in the male of Caridina wangan is elongated elliptical blade-shaped with the middle part a little wider, and the appendix masculina of the second pleopod is club-shaped, with many thick and long thorns. The endopod of the first pleopod in the male of Caridina lineatus is elongated elliptical blade shaped, widest at the middle part, and the appendix masculina of the second pleopod is spindle-shaped, with dense long spines. These morphological characters of the atyid shrimps could be differentiated from closely allied species Caridina serrata Stimpson, 1860. CoXI and 16S rRNA genes were employed to analyze the phylogenetic relationship of the individuals of Caridina wangan and Caridina lineatus and established a ML tree. According to the results of CoXI, Caridina wangan clustered most closely with Caridina baoting and Caridina tetrazona, the genetic distance between Caridina wangan and Caridina baoting is 14.14% and the genetic distance between Caridina wangan and Caridina tetrazona is 15.04%; Caridina lineatus clustered most closely with Caridina carvernicola and Caridina cantonensis, the genetic distance between Caridina lineatus and Caridina carvernicola is 14.36% and the genetic distance between Caridina lineatus and Caridina cantonensis is 16.00%, the genetic distance values all exceeded the threshold for interspecific differences, which is 3%. According to the results of 16S rRNA, Caridina wangan clustered most closely with Caridina baoting and Caridina tricincta, the genetic distance between Caridina wangan and Caridina baoting is 5.17% and the genetic distance between Caridina wangan and Caridina tricincta is 8.00%; Caridina lineatus clustered most closely with Caridina rubropunctata and Caridina thachlam, the genetic distance between Caridina lineatus and Caridina rubropunctata is 4.63% and the genetic distance between Caridina lineatus and Caridina thachlam is 5.14%, the genetic distance values all exceeded the threshold for interspecific differences, which is 1.5%. The morphological differences and the results of molecular biology identification both support that 2 species of Caridina are new species.