Abstract: The aims were to identify Laminariales germplasm resources accurately and provide the basis for germplasm conservation and protection. The universal primers of ribosomal DNA Internal Transcribed Spacer (Internal Transcribed Spacer of rDNA, ITS) were adopted to amplify the ITS sequences of the undetermined samples by PCR, on the basis of the sequencing, the molecular identification was carried out among 25 samples collected from Japan and Yantai sea area. The results showed that 25 undetermined samples and 16 known species were clustered in different groups by clustering analysis of ITS sequence. Within the species identification trees, the ratings are high. The 25 undetermined samples were clustered in three genera, two families and seven different species respectively. The results of morphological observation conformed to the molecular identification. The primers of Laminariales ITS sequence could be used in rapid species identification as its versatility and high efficient amplification rate.