Objective:To study the influence of sun shade net cultivation on plant growth

premature bolting in Angelica sinensis and growth environmental factors.Method: Four treatments with 1 level at random were designed and repeated 4 times.Large

middle and small seedlings were planted separetly in each test plot.Result: Sun shade cultivation promoted Angelica sinensis plant growth: the plant height increased 13.1 ～ 23.1 cm;percentage of Ditylenchus destructor infected plants decreased 17.5% ～ 33.19%;average fresh root weight increased 26.49 ～ 37.35g;yield increased 1 791 ～ 2 445 kg /hm2;and ethanol extracts content increased 7.08% ～ 10.02%.Premature bolting of middle size seedlings decreased 5% and 5.5% respectively when covered with 75% and 50% sun shade net.50% sun shade net cultivation demonstration showed that monthly average air temperature at 8:00 decreased 0.8 ～ 1.5 ℃

and that at 14:00 decreased 1.4 ～ 1.7 ℃;10 days average air temperature in 8:00 decreased 0 ～ 3.1 ℃

and that in 14:00 decreased 1.0 ～ 2.0 ℃.Monthly average soil temperature in 14:00 decreased 2.1 ～ 3.8 ℃;10 days average soil temperature in 14:00 decreased 1.4 ～ 5.4 ℃.10 days average air relative humidity increased 1% ～ 7%;soil water content increased 1.8% ～ 3.7% 3 days after flurry rain.Conclusion: Sun shade cultivation could effectively promote Angelica sinensis plant growth

improve quality

inhibit premature bolting of middle size seedlings

enhance air humidity and soil water content

significantly enhance yield

reduce Ditylenchus destructor infected plants percentage.