Abstract: Compared with the common drilling, alfalfa seedling in planting with plastic film emerged in advance of tree days, seedling stem height increased 57%,seedling stem wide increased 21.7% and root Length increased 2~4cm. Compared with CK, alfalfa stem height increased 30.77%. Branch increased 12%, Ratio of stem to leave was lower than CK, Yield of alfalfa increased 21.14% in first year of planting with Plastic film and increased 83.64% in second year. Net income in two years comed to 2916.88 Yuan/hm2.