This study was conducted to examine the effect of different types of milking instrument and season on milk composition (fat, protein, non-fat milk solids, milk urea nitrogen and somatic cell count) on Holstein-Friesian lactating cows. Raw milk samples were collected from 20 automatic milking system (AMS) installed dairy farms and 85 conventional milking system (CMS) installed dairy farms. Milk fat, protein, NFMS and MUN contents did not changed between AMS and CMS and different seasons. On the other hand, the average SCC in AMS was $239{ imes}10^3cells/mL$ which was lower than in CMS ($373{ imes}10^3cells/mL$, (p<0.05). In conclusion, present results indicated that SCC in milk might be influenced by AMS. However, this area needed more study to confirm the reason of reducing SCC content from AMS.