Filed experiment was conducted to test the effect of saline water and potassium fertilizers rate on proline and water potential of Pisum sativum L. (Var.Senador Cambados ) leaves . Treatments of the experiment included two levels of water salinity( 2, 7 dSm-1) as a main plot and fertilizer rates as a sub plot. Results indicated that irrigation of plant with saline water 7 dSm-1 and fertilization 150 kg/donum increased proline accumulation and water potential 0.31 mmol/g,-17.00 bar at 9 AM morning and 0.62 mmol/g , -21.00 bar at 3 PM afternoon ,Irrigating plant with a 2 dSm-1 and fertilization 300 kg/donum decreased proline accumulation and water potential of leaves 0.22 mmol/g, -16.00 bar at 9 AM and 0.43 mmol/g,-18.00 bar at 3 PM . Irrigation plants with saline water 7 dSm-1 and fertilizer with 150 kg/ Donum K2SO4 increased Root/Shoot to 0.89 ,while 0.41 after irrigation with 2 dSm-1 saline water and fertilization with 300 kg/ Donum K2SO4 . The Na/K ratio increased to 0.53 under 7 dSm-1 of irrigation water and 150 kg/Donum fertilization and decreased to 0.1 under 2 dSm-1 irrigation water and fertilized 300 kg/ Donum . The results lead to the conclusion that potassium fertilization may reduce the inhibitory effect of increasing salinity of irrigation water on pea.