Mishan and Hoolin are located in the east part of Heilungkiang province.This area is an alluvial plain of the Molin river.The climate of this area belongs to cool-temperate region.According to the observations made on the succession of plant society in this region,we have many evidences to point out the fact that the wet lands are gradually becoming dry.The soils of this region may be representatives of the soil types of the forest moorland region of north-eastern region of china.The soils of this region may be devided into four groups,namely:sod-podzolic soil,gley sodpodzolic soil,gley meadow soil and peat-gley soil.