This work presents an electrical and optical emission diagnostics of radiofrequency (RF) magnetron discharge used for titanium deposition in argon (Ar) and methane (CH4) gas precursor. The plasma was produced in incident power and gas pressure ranges of 20-300W and 15-100mTorr, respectively. We have studied the influence of the system operation parameters (incident power, pressure, proportion of gas precursor) on the self- bias voltage (Vdc) and emission intensity IAr of Ar (750.3nm) line. The results obtained show that the pressure of the optimum operation of the magnetron discharge was around 30 mTorr when the incident power varied from 20 to 300W. The relationship between the intensity of IAr (750.3nm) line and the incident power was established.