This survey was carried out to analyze the constituents of feeds influencing the results of management in 30 dairy farms, in Obucho, Aichiken, Japan. The results analyzed are summarized as follows: 1. The increase of the milk production can be brought about by increasing the percentage of oil meal, silage and soiling crop. 2. The net income of dairy-farming is determined by the feeding scale of dairy cows and net income per-dairy cow. Net income per-cow is determined by the milk production and the management cost per-cow, and the management cost is greatly influenced by the feed cost. 3. The increase of milk production per-cow not only raises the net income of dairy-farming on the short period, but also contributes to grow it through the enlargement of the feeding scale on the long period. 4. The net income of dairy-farming was ￥ 2,380,000 on the large scale, ￥ 1,400,000 on the medium scale and ￥ 680,000 on the small scale. There is a big difference between milk productions per-cow by the above scale. 5. The net income of dairy-farming can be improved to ￥ 239,137 on the large scale, ￥ 142,488 on the medium scale and ￥ 78,090 on the small scale by saving the feed cost. 6. The production cost of milk per-㎏ is less than the sale price of milk per-㎏ (￥ 50.50/㎏) only on the scale over 15 cows. 7. The constituent of feeds and the feeding method should be improved regardless of the feeding scale. 8. In the dairy farms on the large scale the percentage of the formula ration, silage and forage crop was increased, because, such farms are specialized, and restricted in labor supply.