Abstract: ObjectiveEffects of component and content of plate medium on sporulation of thin-walled conidia of Ustilaginoidea virens(Cooke)Takahashi was examined in order to provide an easy and rapid technical way for production of thin-walled conidia.MethodFour conventional U.virens strains(Uv-34,Uv-105,Uv-110 and Uv-111)were used as materials.Using common plate culture technical procedure,effects of both potato content and sucrose content in medium potato sucrose agar(PSA)on sporulation of thin-walled conidia was determined,conidia yield of strains grown on plate medium(PA,PSA,PRA,PXA and PSoA)of potato mixed with water(no sugar)and four sugars(sucrose,ribos,xylose and sorbose)was observed,variation trend of conidia yield produced on plate medium due to the change of culture time was recorded,and sporulation of four strains on plate medium of potato agar(PA)was observed.ResultOn PSA medi-um,the top yield(1.69×106conidia/mL)of conidia was obtained from 10 g/L of sucrose,and top yield(1.18×106conidia/mL)of conidia was obtained from 50 g/L of potato.On plate media PA,PSA,PRA,PXA and PSoA,conidia yields were 6.98×106,4.63×106,11.92×106,0.84×106 and 0.01×106conidia/mL.Conidia yield produced on PSA plate media dropped sharply 5 d after culture,but conidia yield produced on both PA plate media and PRA plate media remained steady or increasing trend within a culture duration of 15 d.All four strains produced conidia normally and abundantly on PA plate media.ConclusionU.virens can produce conidia on conventional plate media with potato on.PA is a medium which is quick and easy to use in daily work for the production of thin-walled conidia of U.virens.PRA is a medium to produce thin-walled conidia with high yield.