Some statistical properties of solar granulation in the photosphere and low chromosphere in an active region are examined. We used velocity, intensity and magnetic field variations obtained at different heights from observations in Ba II λ 455.4 nm and Fe I λλ 1564.3—1565.8 nm. The observations were performed with the VTT at the Observatorio del Teide on Tenerife. Changes in line parameters (line-center depth, half-width, equivalent width, line-center shift) and convective velocities are presented as a function of the magnetic field. We suggest a 16-column model of solar granulation depending on the direction of motion and on the intensity contrast in the continuum and in the uppermost layer (h = 650 km). It is found that the magnetic field prevents changing the contrast sign and direction of motions for convective elements.