This study was conducted to know effects of forage cutting height and inoculants application on chemical composition, fermentation characteristics and fatty acid profile of barley silage. Barley forage(Yuyeon hybrid) was harvested at two different cutting heights(5 vs. 15cm) and applied with or without Lactobacillus plantarum, and ensiled for 0, 2, 7, 28, 49 and 100days. On 0 to 49-d of ensiling, higher cutting height resulted rapid drop (p<0.05) in pH caused by higher lactate content. Crude protein (p<0.01) content of 100-d silage was decreased by inoculation, but increased by higher cutting height. However, neutral detergent fiber and acid detergent fiber contents were decreased (p<0.05) by both inoculation and cutting height. In vitro dry matter digestibility was improved by higher cutting height (p=0.01), while yeast and mold counts were reduced (p<0.0001). The C18:3n-3 content in barley silage was decreased (p=0.001) by inoculation, but increased (p=0.034) by higher cutting height. The DNA analysis indicated L. plantarum dominating fermentation in inoculated silages. The results showed that higher cutting height can improve silage quality in terms of increasing crude protein content and digestibility as well as reducing yeast and mold counts in barley silage.