To study the chemical constituents of sea anemone, Anthopleura stell Verrill.Methods　The chemical constituents were isolated and purified by chromatographic methods and their structures elucidated by chemical evidences and spectra data.Results　5 nucleosides were obtained and identified from the ethanolic extract as 2-hydroxy purine (Ⅰ); deoxyinosine (Ⅱ); 1-methylxanthosine (Ⅲ); deoxyguanosine (Ⅳ), and deoxyribo-thymidine (Ⅴ).Conclusion　Compound Ⅲ was a new natural product， while the others were found from sea anemone for the first time.