The pollen dispersal and its spatial distribution was studied in Pinus massoniana clonal seed orchard located in Taizishan,Hubei Province.The results showed that the pollen quantity in the air in the clonal seed orchard of Pinus massoniana had a date rhythm of low-high-low.The pollen dispersal peak stage appeared in the mid of the whole pollen dispersal period with a duration of 3-5 days.The pollen quantity in the air had significant differences among dates and had a time regular of low-high-low with the peak time occurring from 10:00 to 14:00.However,the peak time was impacted by climatic factors.The pollen quantity in the atmosphere outside the seed orchard decreased with the distance increase showing an S curve regression.The pollen dispersal and its distribution were affected by a lot of factors,such as wind speed,relative humidity,temperature,terrain and so on.Based on the characteristics of the pollen dispersal and its distribution outside the seed orchard,the minimum isolation distance for a seed orchard was more than 1 000 m in order to prevent pollen pollution by external pollen.