Triperpenoid saponins are secondary metabolites that are produced by many different plant spices. The natural role of saponins in plants is likely to be in defense against attacked by pathogens. Also, saponins are used as drugs , foaming agents and test modifiers.The aim of this work is understand the changes of saponin contents in Bellis Perennis L. under salinity stress. Since NaCl stress is major factore limiting crop production ,it is important to understand how plant respond to this stress. In this investigation , the plants were treated by salinity stress , the work was done as fallow: the plants were placed in separate pots, and treated with 0 mM NaCl as a control plant, 15 mM NaCl, 25 mM NaCl, 50 mM NaCl, 75 mM NaCl and 100 mM NaCl for 40 days. After 40 days, symptoms of salinity stress were seen as signs of cloresis and reduction of leaf area; also, in 100mM NaCl, all treated plants died. However, others tolerated lower level of salinity. After 60 days the plants were harvested and the total saponin was extracted and estimated with HPLC method from dry root s of Bellis perennis L. Results show that the content of saponin was increased in 15 mM NaCl and higher levels of salinity caused the plants to decrease the content of saponin in comparison with control plant. The results indicate a kind of response of the plant to environmental stresses.