The objective of this work was to establish an approaching method for TMR feeding system in the farm situation by testing the effects of herd-mix feeding system on the performance of lactating cows. Fifty six Holstein cows were fed for the experimental period of 16 months. Prior to test the herd-mix feeding system, animals were kept on conventional feeding system for 4 months, separate feeding of forage with concentrate, then provided 3 types of herd-mix rations formulated by mean level of energy concentration requirement of higher 1/2 ranker in each herd for remaining 12 months to compare the effect on milk yield performance of animals with conventional feeding system by using a switch-over method. The herd-mix feeding system influenced substantially upon the improvements of milk yield(P<0.01) and milk fat percentage(P<0.05). In all of lactational ages, milk yield and milk fat were enhanced by the herd-mix feeding system. Especially, actual milk yield(AMY) and milk fat in the 1st lactating cows, and AMY and 4.0% fat corrected milk yield(FCM) in the 2nd lactating cows were increased signiticantly by the herd-mix feeding system(P<0.05). In the early and mid-stage of lactation, the herd-mix feeding system showed higher AMY and FCM compared with the conventional feeding system although the milk fat was not different. AMY, milk fat and FCM in the late-stage of lactation were increased generally by the herd-mix feeding system. Especially, milk fat and FCM obtained by the herd-mix feeding system were significantly higher than those by the conventional feeding system(P<0.01). The herd-mix feeding system showed a good type of milking curve with a higher persistency of FCM(93.24%) than in conventional one(92.69%). The income over feed cost with the herd-mix feeding system was lA-fold higher than that with the conventional feeding method. In conclusion, the results of this work suggest that the herd-mix feeding system based on a correct level of energy concentration of TMR and well-determined feed ingredients increases not only milk yield of dairy herd by enhancing the performance of cows in early to mid stage of lactation with improved milk persistency but also gross income of dairy farm.