The physical, chemical and bacteriological qualities of the raw milk on handling stages, farms and seasons were investigated to make basic data on the improvement of raw milk quality. The bacteriological quality changes of raw milk according to handling stages were as follows: the number of live bacteria per milliliter milk were 180,000 before filtration, 320,000 after filtration, 6,100,000 before transportation to the milk plant and 8,100,000 at the dairy plant; the number of coliform bacteria per milliliter milk were 4,700 before filtration, 7,300 after filtration, 78,000 before transportation to the milk plant and 87,000 at the milk plant. It was discussed that the filtration process increased the number of bacteria because of contaminated filter clothes and breaking of dirt during filtration. The necessity for the introduction of bulk tanks and refrigerated truck tank was emphasized. The number of bacteria in cleaning water and equipments were as follows the number of live bacteria per milliliter were 30,000,000 in udder washing water in a band milking and 1,300,000 in a machine milking, 270,000 in a milking machine, 60,000/㎠ in filter clothes, 44∼1,200 in running water, however, there was no coliform bacteria in running water. The bacteriological quality of 179 samples collected from milk cans carried from 9 farms every month for a period of one year was as follows: the average number of live bacteria was 7,100,000/㎖, the ratio of Grade A milk with colony counts under 100,000/㎖ was 11% of the samples examined, and the ratio of a tolerable quality with colony counts under 2,000,000/㎖ was 55%; the average number of coliform bacteria was 310,000/㎖ and the ratio of coliform negative samples was only 3.4%. Although there were much differences between dairy farms in the raw milk quality, there was not much differences between seasons. It was suggested that the cleaning of barns and milking equipments was not properly done during cold winter season. The necessity of a campaign for the improvement of raw milk quality was emphasized.