The chromate adsorption capacities of Pachymeniopsissp.werecomparedwithrespecttosamplingtimes from February to July. Although the size and mophology of the alga varied according to sampling time, no seasonal variation in the chromate adsorption capacity of the alga was found. Since Pachymeniopsis sp. grows extensively from April to May, this period is taken to be the best time for mass collection of the alga.