Vanadium-titanium catalysts modified with sodium or potassium additives (1-15 wt.% of Me2O) have been studied in methylpyrazine ammoxidation. Introduction of the additives results in a decrease in the activity and selectivity of the catalysts due to formation of low-active phase -bronzes (MeV6O15) and vanadates (alpha-NaVO3, KVO3 and K3V5O14). The active sites of the modified samples, similar to those in the V-Ti-O catalyst, are found to be V5+ cations strongly bound to TiO2 and located in a significantly distorted octahedral oxygen environment.