Based on the results of chemical analysis, thermoanalytical curves and IR absorption spectra the resulting product proves the individuality and chemical formula of sodium mannitolborate C6H12O6B(OH)2]. From the specific electric conductivity (25±0,10 C) and optical rotation angle data (18 +20C) in the polyol-boric acid-water systems the stability constants of sodium mannitolborate were calculated using the classic laws of electrochemistry. The results show that the most stable are two anions - mannitoldiborate [Mannitol B2]-2 and mannitolborate [Mannitol B]-, which exists in the alkaline and neutral parts of the systems at the total concentrations of 0.25, 0.5 and 0.75 M [1]. We provide the use of sodium mannitolborate as a corrosion inhibitor in combination with additives for steel and non-ferrous metals (aluminium, copper, brass) in water and water-ethylene glycol mixtures (1:1). We investigated the corrosion within the temperature range of 20-70 0C and under dynamic conditions. With reference to the corrosion gravimetric measurements, sodium mannitolborate is an excellent inhibitor in water media for steel, copper, brass, aluminium and its combination with other additives influences insignificantly the corrosion protection degree (98-88%). Therefore, sodium sorbitolborate itself is effective at all investigated concentrations and can be used in water media to prevent corrosion Sodium mannitolborate and additives in water-ethylene glycol media (1:1) shows, that sodium mannitolborate is effective inhibitor of corrosion for steel and under optimal conditions inhibition effenciency reaches 95% (2,0 g/l). The compositions G and H on the base of sodium mannitolborate are very effective for steel (protection effect 97%, 99%) accordingly. Sodium mannitolborate and compositions do not protect copper and aluminium. The composition with sodium mannitolborate H is very effective for brass (protection effect 95%).