This experiment was conducted to compare the seed productivity of Spring sown Italian ryegrass(Lolium multiflorum Lam.) depending on the seeding rates(20kg/ha, 30kg/ha, 40kg/ha) in Gangwon region. The experiment was a randomized block design with three replications. The test plots were located in alpine areas of about 600 m above sea level in Gangwon province. The tested Italian ryegrass variety was ‘Greencall’ developed by the National Institute of Animal Science, RDA. Italian Ryegrass was sown on March 26, 2020, and the seed harvesting was on the 60th day(2 July) from heading date. The heading date was May 8 with no difference, There were no significant differences in the agronomic characteristics including plant height. 30kg/ha seed rate was the highest at 146.8 seed/spike and 40kg/ha seed rate was the lowest at 114.7 seed/spike for the number of seeds per spike. The number of spikes per unit area was the highest in 40kg/ha at 886/m2 and the lowest in 20kg/ha at 750/m2. The yield of seed and straw was the highest in 40kg/ha at 1,288kg/ha and 2,970kg/ha respectively, but there was no difference. From the above results, the production of Italian ryegrass seeds through spring sowing in the Gangwon region is not much than autumn seeding, requiring the input of various technologies to increase productivity in the future, and it is desirable to determine the production cost through economic analysis was evaluated.