Co-Cr alloy films (20 at.% Cr) were deposited by DC planar magnetron sputtering under various conditions, e.g. film thickness, Ar working gas pressure, deposition rate, substrate temperature, annealing temperature and negative bias voltage. The structure of the films was analyzed systematically with the X-ray diffraction technique. The preferred orientation of crystallites (texture) was evaluated from the full width at half maximum of rocking curve of HCP (0002) crystal planes, while the (0002) and (0004) diffraction line profiles were interpreted by the analytic function method. The results show that the effective crystallite size (i.e. the coherent length in the film thickness direction) is normally in the range of 20-90 nm, and the microstrain is about 3-12 x 10(-4). The increasing of bias voltage obviously makes the microstrain increase. In addition, the decreasing of the effective crystallite size corresponds to the degradation of the preferred c-axis orientation for all conditions under consideration, suggesting that the existence of structural defects (such as voids, stacking faults, Cr segregation, and twinning etc.) interrupts the coherency along the film thickness direction and induces a random orientation of crystallites as well.