Using data obtained with the Michelson Doppler Imager (MDI) onboard the Solar and Heliospheric Observatory (SOHO), we have conducted a statistical study of the relationship between plasma flow Doppler velocities and magnetic field parameters during the appearance of active regions at the solar photospheric level. We have examined 224 emerging active regions having different spatial scales and positions on the solar disc. The following relationships have been analysed: 1) those between the negative Doppler velocities and the position of active regions emerging on the solar disc; 2) those between the negative and positive Doppler velocities and the magnetic field parameters in the ac-tive regions emerging near the solar disc centre (the vertical component); 3) those between the negative and positive Doppler velocities and the magnetic field pa-rameters in the active regions emerging near the limb (the horizontal component); 4) those between the mag-netic flux growth rate and the strength of emerging magnetic fields; 5) those between the Doppler velocities and the magnetic field parameters during the first hours after the appearance of active regions with the total unsigned magnetic flux at the peak of their development.