In this study, the effect of background electrolyte and the ionic strength on electrochemical deposition of chromium using trivalent chromium baths is considered. Candidate baths were first chosen after a series of testing in Hull cell, then they were conducted by using direct current electroplating potentiostat in the bath. The working potentials of this process and quality of the chromium deposits were considerably depended on the ionic strength of the baths as well as different source of anions and cations. Sequences of electrochemical plating were performed to investigate the optimal range of ionic strength, and to get the most suitable kind of anions and cations for the popular baths containing trivalent chromium. The results showed that the conditions in which the ionic strength within a range of 7.75 to 10.75 (sodium sulfate in the range from 0.25 M to 1.25 M, magnesium sulfate in the range from 0.19 M to 0.94 M), the pH of the bath from 1.5 to 2.0, bath’s temperature from 30 °C to 35 °C, current density within the range from 4.5 to 7.0 A/dm², the satisfying Cr-coatings were obtained with a thickness of several tens of micrometers, revealed a good appearance with a smooth and good luster surface.