The NO-induced intracellular free calcium concentration (［Ca²⁺］_i) rise and the inhibiting effect of selenium on this process were determined by using Fura-2/AM fluorescence measurement method in a human umbilical vein endothelial cell line: ECV-304. Experimental results indicated that there was a fast rise of ［Ca²⁺］_i by the treatment of S-nitrosoglutathione(GSNO), a donor of NO. The rise of ［Ca²⁺］_i was inhibited by Hb, a scavenger of NO. These results suggested that this rise of ［Ca²⁺］_i was induced by NO. There was no effect on ［Ca²⁺］_i response to NO by removing calcium ion from bath, or by adding the non-selective calcium channel antagonist, CdCl₂（1 mmol/L）to the bath. When the cells were pretreated by sodium selenite(1 μmol/L),the rise of ［Ca²⁺］_i induced by NO was obviously inhibited. This result suggested that selenium can inhibit calcium store release.