Protoceratium reticulatum,a marine dinoflagellate that produces yessotoxins (YTXs), is common in coastal waters worldwide and can form toxic algal blooms. There are marked differences in its growth and toxin-producing characteristics in different areas. This study investigated the effects of temperature and nutrient (N, P) limitation on the growth and toxin production of P. reticulatum recently isolated from the North Yellow Sea. The results showed that temperature and nutrient limitation affected growth and toxin production of the alga to different degrees, but nutrient limitation had a more significant influence. Lower temperatures were more suitable for the growth of P. reticulatum. Growth of algal cells in L₁-Si medium without nutrient limitation was best at 15℃. P limitation greatly reduced the specific growth rate and cell density (P < 0.01), and shortened the duration of the exponential and stationary phases. N-limited cultures, in contrast, resulted in a growth rate and maximum cell density similar to those in L₁-Si medium, but with a shorter stationary phase. At all temperatures, both N and P limitation were favorable for the accumulation of YTX in algal cells, which was particularly marked in the latter. The maximum YTX content of 92.6pg/cell was observed in 1/10P medium at 15℃ at the end of the stationary phase. This was approximately 3.8 times and 7.1 times that of the YTX in the N limited and L₁-Si medium at the same culture temperature, respectively. Changes in temperature had different influences on the content of intracellular YTX in N-and P-limitation cultures. In the range of 5-15℃, temperature change had a negative effect on YTX increase under N limitation, whereas in P-limited medium, the effect was positive. In all culture conditions, the YTX concentration in the filtrate began to increase during the stationary phase. Compared with L₁-Si, both N-and P-limited media were not conducive to the release of toxins. Higher temperature helpful to YTX release in the L₁-Si and N-limited media, but it did not significantly affect that in the P-limited medium.