Efficient use of natural and biological cycles such as nitrogen fixation by legumes may stimulate yield of the non-legumes crops in an intercropped system. To evaluate spring barley and annual medic intercropping, an experiment was conducted in the research field of Tehran University in Karaj, Iran, in 2009-2010 growing season. Randomized complete block design (RCBD) with four replications and 14 treatments were used. Treatments included: B1: 1M, B2: 2M, B4: 4M, B6: 6M, B6: 2M, B4:2M, B2: 4M, B2: 6M, B100%: 20%M, B100%: 40%M, B40%: 100%M, B20%: 100%M and two additional treatments of barley and annual medic sole crop were established. The highest dry matter yield for barely and annual medic was achieved from sole crop (2900 kg ha-1 for barely and 1773 kg ha-1 for annual medic, respectively). The highest forage water soluble carbohydrates (WSC=15.42%), forage crude fiber (CF=38.40%), silage neutral detergent fiber (NDs=44.72%), silage pH (pH=5.31) belonged to sole crop of barley. Also, the highest silage acid detergent fiber (ADF=26.42%) and forage acid detergent fiber (ADF=30.88%) belonged to sole crop of annual medic. The highest seed yield for barely and annual medic was achieved from sole crop (1907 kg ha-1 for barely and 877 kg ha-1 for annual medic, respectively) and the maximum harvest index (HI) was for B2:6M for barley (34.75%) and B2:2M for annual medic (28%). The highest land equivalent ratio for dry forage yield (LER=1.232) was obtained from H1:1M. The highest land equivalent ratio (LER=1.29), monetary advantage index (MAI=1329877.5 toman) and relative crowding coefficient (RCC=2.79) for seed yield obtained for B6:2M mixture. Results suggested that the suitable mixture for dry matter yield was B1:1M. For achieving better silage and forage quality, higher ratio of annual medic in mixtures with barley is necessary. Results also suggested that the suitable mixture for seed yield was B6: 2M.