Research on the soil moisture characteristics in Alnus cremastog yne and A lnus formosana forestland with the red soil developed from quaternary red earth in Northern Hu'nan is conducted. Results show that maximum moisture content for the Alnus cremastogy ne litter is 24.76t/hm, which is 1.22 times of that of the A lnus formosana. By both the total capillary porosity and non-capillary po rosity, landuses can be ranged in the order of A lnus formosana plantations > A lunus cremastogy neplantations > wasteland. The maximum soil moisture content for the Alnus formosana is 24.55 mm. By the infiltration parameter in 0 -45 cm soil layer, landuses can be ranged in the order of Alnus formosana plantations > Alnus cremastogy neplantations > wasteland. This indicates that the Alnus plantations could improve soil structure and make the soil to keep very good soil moisture characteristics.