Out of 700 bulk milk samples collected from Tau-Yuen dairy area were studied by somatocell count and kecteriai culture. The result indicad that the average of cell count was 155,000/ml with range ketween 0～2,260,000/ml, 94% of the samples had cell count kelow 300,000/ml. The cell count kelow 500,000/ml covered 99% of the total samples. It showed small variation in cell count among the samples studied. The fluctuation of the cell count among months was influenced by the morbidity of sukclinical mastitis of the herd, CMT can ke served as gactical method for detecting abnormal cell count in the field. Both suphykococcus aureus and other Steptctxd were isolati from 14% of the samples. Steptcoxcus agalactiae was only in 028%. Somatxell count mny th bacterial culture of bulk milk seems to ire ictical method for controlling the milk quality and mammary health of cows.