The objective of this study was to evaluate effects of feeding purple corn silage (Zea mays L.) on productivity and antioxidant function of lactating cows. It was hypothesized that feeding a purple corn silage (AX-152; Nagano Animal Industry Experiment Station and Takii & Co. Ltd.) would increase milk production as it contains more anthocyanin, an antioxidant, which removes active oxygen from the body. Sixteen Holstein cows (8 primiparous cows and 8 multiparous cows, BW: 574.5 ± 10.0 kg, mean ± SD) in mid-lactation (DIM: 136.7 ± 10.4 d) were assigned to one of 2 treatments with an effort for balanced parity, BW and DIM between the treatments. Experimental diets contained either AX-152 corn silage (ACS; 31.2% DM, 8.4% CP, 40.2% NDF, and 26.6% starch) or a conventional corn silage (CONT; 30.5% DM, 8.7% CP, 42.1% NDF, and 26.5% starch) at approximately 32% of diet DM. The ACS and CONT were ensiled for more than 3 mo before the study. Treatment diets were fed as TMR ad libitum for a 12-week period from February 1, 2016 to April 25, 2016. Cows fed the ACS increased (P < 0.05) milk yield (31.7 vs. 29.2 kg/d) and concentration of blood superoxide dismutase, an antioxidant enzyme (9,588 vs. 8,946 U/mL), compared with those fed CONT. In addition, the ACS treatment decreased serum total protein concentration (6.9 vs. 7.3 g/dL; P < 0.05) and increased serum aspartate aminotransferase concentration (90.8 vs. 81.7 U/L; P < 0.05) compared with CONT although anthocyanins was not detected in plasma or milk. However, it is noteworthy that anthocyanin concentration in the ACS decreased over the 12-week experiment period; 70 mg/kg DM for the first 4-week period, 20 mg/kg DM for the second 4-week period, and not detectable for the last 4-week period. Anthocyanins in the CONT were not detected at any time points. These results suggested that feeding purple corn silage may increase antioxidant capacity and milk production of dairy cows, but the long-term feeding effects need to be confirmed in future studies as anthocyanins may be degraded over time in silos.