Using micro-lysimeter,we observed the condensed water in the soils of variously degraded alpine meadows in Fenghuoshan basin of the Qinghai-Tibet Plateau.The formation mechanism of condensed soil water was further analyzed according to the observation data.The results showed that condensed soil water came mainly from two sources: water vapor in the air and in the vadose zone migrated upward under the action of the geothermal gradient.The water vapor from the vadose zone was significantly greater than that from the air.The condensation mainly occurred during night from 20:00 pm to 8:00 am in the next day,and the largest amount of water was condensed in early morning between 6:00 am and 8:00 am.Meanwhile,the condensation mainly occurred within the upper 5 cm of the soil profile.The amount of condensed water decreased with the degradation of alpine meadows,and the occurrence of condensation was of great significance in maintaining the balance of alpine meadow ecological system.