The goal of this study was to evaluate the effects of lactation stage and individual performance on milk cis-9, trans-11 conjugated linoleic acid (CLA) content in dairy cows. In experiment 1, the milk cis-9, trans-11 CLA content from dairy cows in early ($0.33{pm}0.014%$), middle ($0.37{pm}0.010%$), and late stages ($0.44{pm}0.020%$) showed significant differences (p<0.05); and the individual contents of the major fatty acids, especially cis-9, trans-11 CLA in cows of the same lactation were also variable. In the second experiment design as a validation test, our results once again showed that the individual contents of cis-9, trans-11 CLA were various, and a difference of about 2-fold (0.55% vs 0.95%) was observed, although the animals were offered same diet. These data demonstrated that lactation stage and individual performance have considerable effects on milk cis-9, trans-11 CLA contents.