Porphyra haitanensis is one of the most important economic marine crops of China.For any cultivar,the correct identification of species or forma of the cultivated strains is necessary to ensure a well-bred cultivation and good production quality.However,because the gametophytic blade of Porphyra is morphologically simple and marked variations can occur as environmental conditions change,it is very difficult to precisely identify the species or forma of cultivated strains based only on their morphological characteristics.With new advances in molecular biology,molecular markers and DNA fingerprinting techniques have become routine for the identification and classification of many crops,including seaweeds.The strain of “Z-26” of P.haitanensiswas selected by the laboratory of germplasm improvement and the application of P.haitanensis in Jimei University which has the characters of high-temperature tolerance and high yield,and it has been widely cultivated in south China.In order to construct the technology of variety identification for “Z-26”,firstly,300 primers of RAPD were used to scan the specific markers of 6 new strains of P.haitanensis and 9 specific RAPD markers of “Z-26” were selected.After cloning and sequencing,two specific RAPD markers of “Z-26” were transformed into the SCAR markers successfully,the length of the 2 SCAR markers was 540 and 242 bp,respectively.Secondly,after verification by 4 different experiments,we can affirm that the 2 SCAR markers were the specific and stable markers of “Z-26”.At last,based on the 2 SCAR markers,after optimization of experimental conditions,the technology of multiplex PCR which was used to identify the variety of “Z-26” was constructed.The result supplied a simple,fast and reliable technigue for variety identification of “Z-26”.