In this study conducted as a pot experiment under laboratory conditions, in addition to NaCl (100 mM), some organic compounds, ascorbic acid (0.5 mM), salicylic acid (0.1 mM), nitric oxide (as SNP;100 µM), proline (10 mM) and some inorganic compounds such as silicon (2 mM), calcium (10 mM) and potassium (10 mM) were applied to pepper plant foliarly. Thus, general development situation in pepper plants under salt stress as well as comparative effects of these organic and inorganic compounds on lipid peroxidation and antioxidative defense system of pepper plant were investigated. At the end of analyses made during the study, membrane permeability (EC %), proline, chlorophyll and carotenoid contents, some antioxidative enzyme activities (SOD, POX CAT) were revealed, furthermore some plant growth parameters were determined. At the same time, the content of some macro elements (Na, Ca, K and P) in leaves were analyzed. It was observed that membrane permeability, lipid peroxidation, proline content and antioxidative enzyme activities increased in pepper leaves under ascending salinity stress, however, these parameters decreased with the addition of some organic and inorganic compounds. Additionally, the content of leaf macro element, which showed a decline with salinity, and also plant length, stem diameter, stem-root fresh and dry weights changed positively with the addition of some organic and inorganic compounds to the growth media. It was observed that among these compounds AsA, NO and K were the most effective ones for suppression of lipid peroxidation, the regulation of enzymatic antioxidative system and leaf dry weight, respectively. Consequently, it was thought that the ones having the greatest effect on diminishing salinity stress and the ability of regulating plant metabolism by supporting antioxidative system among organic and inorganic compounds, of which activities were compared in pepper plant grown under salinity stress and controlled conditions, could be used under salinity.