A simple, sensitive and accurate method for spectrophotometric determination of Dalacinphosphatehas been established. The method is based on the reduction of atomic absorptioncalcium ion by phosphate. Because, there is a phosphate mole in every Dalacin mole structureand with measurement of phosphate, Dalacin is beyond measurement too. Therefore, the reactionbetween acidic hydrolysis products of antibiotics with the mixture of calcium ion evaluated forthe spectrophotometric determination of mentioned drug in formulations. Experimentalparameters related to the performance of atiomic absorption spectrometry (AAS), such asconcentration of calcium ion, reaction time and temperature were investigated and optimized.Under the optimized conditions, the limit of detection (3σB) and relative standard deviation(RSD, n=4) were 1.75 μg mL-1 and 1.4 %, respectively. The results obtained agreed with thoseobtained by the USP method.