The seed proteins, especially legume proteins, are considered cheap and easily obtained, although they have low functionality. In this way, many studies have been carried out to improve the functional properties such as solubility, gelling capacity and emulsion stability of these proteins. Considerable interest has been focused on the relationships between structure and physicochemical properties of seed proteins used in the food and biotechnology industries. Vicilin is the secondary storage protein fraction of Pisum sativum, corresponding to 15% - 35% of the total protein content of the mature seeds. The aim of this work was to investigate the effect of phosphorylation with sodium trimetaphosphate (STMP) in different concentrations (1% and 4%) on functional properties and structural stability of the pea vicilin exposed to physical (hydrostatic pressure and temperature) and chemical (pH and salt) agents. The Vicilin was purified by ammonium-sulfate precipitation and the phosphorylation was carried out by incubating pea protein isolate and sodium trimetaphosphate in borate buffer at pH 11 for 3 hours at 37 °C. The results showed that solubility of the phosphorylated Vicilins with 4% STMP, was superior to unmodified Vicilins. The chemical phosphorylation decreased 80% of the gelling capacity. The isoeletric point of phosphorylated and control Vicilin changed in the presence of NaCl 0.5 M, resulting in a decrease of the solubility at pH 1-2. The gelling capacity of control and phosphorylated Vicilin in the presence of NaCl 0.5 M decreased 80% when compared with control Vicilin without NaCl. Phosphorylation promoted improvement in protein stability, as probed by high-pressure and temperature-assisted perturbation experiments by intrinsic fluorescence spectroscopy. No observable effects on stability due to protein concentration in high-pressure experiments were observed. These results indicated that chemical phosphorylation is an efficient method for controlled modification of the physico-chemical properties of Vicilin.