Abstract: This study was carried out between 2002-2004 in Suleyman Demirel University Agricultural Faculty Experimental and Application Farm in order to determine the effect of different Hungarian vetch-barley mixture rates and harvesting periods. In the experiment, the effects of three different harvesting periods (Pre-blooming, 50% blooming, fruit ripening) and five different mixture rates (25% vetch+ 75% barley, 50% vetch +50% barley, 75% vetch+ 25% barley only vetch and only barley) on plant length, herbage yield, dry matter yield and crude protein yield were investigated. At the end of the research it was found out that when the rate of barley increased in the mixture plants became taller, herbage yield and dry matter yield increased and crude protein yield decreased. The highest herbage and dry matter yield were obtained between single barley and the mixture of 25% vetch + 75% barley, pre-blooming and 50% blooming periods the highest value of crude protein yield was obtained in the mixture of 75% vetch+ 25% barley. Harvesting period didn`t effect the plant length and crude protein yield.