In this paper, the authors announce the survey results the optimum conditions for optical measurement of paracetamol (PAR) and chlopheninamin maleate (CPM), resulting in simultaneous determination of PAR and CPM in the letters show the method phases only be applied (with error less than 5 percent) when PAR levels not exceed 60 times larger than CPM, and CPM determined in dmg Slocol PAR, Detazofol, Pamin and Pacemin Kalman filtering method for the recovery of den 101 PAR from 99.3 percent, 7 percent, and CPM nom 99.5 percent to 100.8 percent.