This study was conducted to evaluate the effect on quality characteristics of grass-fed cow’s milk (GM) and conventional feed-fed cow’s milk (CM) with various conditions of non-thermal high-pressure processing (HPP) sterilization process. The sterilized GM and CM stored at 5℃ and 10℃ for 14 days and their quality characteristics during storage was evaluated. The pH and titratable acidity changes of HPP sterilized milk were maintained acceptable level 6.7-6.8, 0.14-0.16%, respectively. HPP sterilization was efficient in the reduction of total bacterial population to decrease the level of 4-7 Log CFU/ml compare to those of unsterilized control milk, and coliform bacteria was not detected in the HPP sterilized milk. Non-thermal HPP sterilization processing was not affected milk fatty acid composition compare to those of low temperature long time process (LTLT) sterilized milk. GM has lower ratio of n-3:n-6 unsaturated fatty acid level than those of CM. In the sensory evaluation of GM and commercial milk products, overall consumer acceptance of HPP sterilized GM was higher than CM and LTLT commercial product. In conclusion, the effects of HPP was comparable with conventional LTLT sterilization process to control undesirable microorganism in the milk products with minumal nutritional and chemical changes.