Magnetic Circular Dichroism (MCD) represents the difference of absorption of left and right circularly polarized light in the presence of the external magnetic field applied parallel to the direction of the light propagation. MCD has some attractive features as compared to other experimental techniques. Due to signs of individual MCD bands the corresponding spectrum has much higher resolution than the absorption one. The MCD technique is site selective, individual centers can be studied. To perform the measurements one needs only a small amount of paramagnetic centers in the sample. Even for a frozen solution an orientational selectivity is present. As a result, this technique is widely used for study of the role of transition metal centers in different chemical compounds.   In the present contribution the basic description of the MCD method is given. After that it is illustrated what information can be obtained with the use of this technique. The analysis of the MCD spectra can be performed in two ways, namely, the simulation of the MCD spectrum (lines positions, signs and intensities) and analysis of MCD saturation magnetization curves. Examples of both approaches are given. Among the studied systems there are exchange coupled Cu tetramer with the cubane-like structure, Co(II) compound demonstrating thermally induced low-spin to highspin transition and exchange coupled Co(II) dimer with unusual MCD saturation magnetization behavior. In all presented examples the MCD measurements are supplemented by magnetic measurements and accompanied by theoretical calculations.