We investigated the growth and phosphate uptake of a toxic dinoflagellate, Gymnodinium catenatum, isolated from Yeosuhae Bay, South Korea. A short-term phosphate uptake experiment revealed that its maximum uptake and the half-saturation constant were 1.39 pmol/cell/hr and $2.65{mu}M$, respectively. In a semicontinuous culture, the maximum specific growth rate and minimum phosphorus cell quota of G. catenatum were 0.39/day and 1.27 pmol/cell, respectively. Thus, G. catenatum is a poor competitor in terms of inorganic nutrient use and is unlikely to form blooms in Yeosuhae Bay.