Studies on the marine flora of the China coast region of the Western Yellow Sea, including the Po-hai (Gulf of Pe-chi-Li), were first made by the German naturalist G. v. Martens who published in 1866 the first list of marine algae of Yentai (Chefoo) enumerating 17 species. Since then 44 additional papers dealing with the benthic marine algae of this region have been published. A critical evaluation of the records as appearing in these 45 papers has been made. It was found that in the earlier papers, a rather low percentage of the records can be accepted with certainty. For instance, among the 17 records of Martens (1866) only 7 or approximately 41 % of the total number of species, and among the 18 records of Debeaux (1875) only 6 or about 33% can be accepted. From 1866 to 1949, 24 papers have been published, and a critical studies of the records resulted in accepting 129 species and rejecting 38 species, with 15 species remaining to be verified. Since 1949, 21 papers have appeared. Critical studies of the records reported in these papers added 56 species to the marine flora of this region, and rejected 2 species, with 6 species remaining to be verified. All together, there are now 185 species of benthic marine algae reported from the Western Yellow Sea and accepted by the present authors, including 26 green, 47 brown, 35 blue-green and 77 red algae. A check list of these species has been presented and their occurrence in various places on the Western Yellow Sea coast noted, together with the literature involved. Of the remaining recorded species, 39 have been rejected and 21 are awaiting further varification.