This study was carried out to determine the utilization possibility of sea water in spinach plant cultivation, and to evaluate the effect on yield and growth parameters of spinach irrigated with sea water diluted at different rates. The experiment consists of 5 different irrigation water salinity. The tap water was taken as a control (T1; 0.33 dS/m), and 10% (T2;4 dS/m), 20% (T3; 7 dS/m), 30% (T4; 10 dS/m) and 40% (T5; 13 dS/m) rate of sea water diluted with tap water. According to results, the highest average fresh yield and dry matter values were obtained at T2 (%10) seawater treatment. Both T2 (10%) and T3 (20%) seawater treatments lead to increased fresh yields and dry matter compared to control conditions (T1). While using dilution 10% and %20 seawater for irrigation fresh yields increased approximately 27% and 8.5% respectively but when irrigated with 30% and 40% yields decreasing about 28% and 72% respectively. As with the yield results, the 4 dS/m seawater salinity level caused an increase in leaf heights and leaf number compared to the control treatment. In conclusion, this study shows that seawater can be used successfully when diluted 10% with good quality water without affecting the growth parameters and yields of spinach.