We propose a new method for determination of the rotation velocity of the galactic spiral density waves , correspondingly , the corotation radius , r _ { C } , in our Galaxy by means of statistical analysis of radial oxygen distribution in the galactic disc derived over Cepheids .
The corotation resonance happens to be located at r _ { C } \sim 7.0 - 7.6 kpc , depending on the rate of gas infall on to the galactic disc , the statistical error being \sim 0.3 - 0.4 kpc .
Simultaneously , the constant for the rate of oxygen synthesis in the galactic disc was determined .

We also argue in favour of a very short time-scale formation of the galactic disc , namely : t _ { f } \sim 2 Gyr .
This scenario enables to solve the problem of the lack of intergalactic gas infall .