Abstract: The phylogenetic relationships of three species of Porphyridium, Porphyridium aerugineum 755, Porphyridium purpureum 806 and Porphyridium cruentum were analyzed by RAPD. Twenty-five random primers of high reproducible and stable quality were screened from 50 primers. There were 186 polymorphic fragments of 233 total fragments. The cluster analysis results were indicated as follows: The average genetic distance among P. aerugineum, P. purpureum and P. cruentum was 0.455. The genetic distance between P. aerugineum and P. cruentum was 0.556. The genetic distance between P. purpureum and P. cruentum was 0.396. The results show that RAPD technology can be used for genetic diversity researches in species of Porphyridium.

Key words: Porphyridium, RAPD, genetic diversit