Abstract: This paper takes an overall review on the former researches firstly.Focus mainly on the concept,types,scaling effect,key problems of DEM scale,as well as its impact on DEM based digital terrain analysis.A few key research topics were put forward through an overall analysis of the research development in recent years,i.e.the property of scale conflict and scale matching between natural and DEM simulated surface;the principle and mechanism of how the spatial scale parameters impact the terrain analysis,the heterogeneity effect in terrain analysis within DEM grid cells.And then,from the view point of regional scale level,both the certainty and uncertainty property in digital terrain analysis should be investigated.In addition,more work should be done to establish a scale depended multi-scaled terrain analysis model as well as DTM scale converting models.Finally,the research development tendency was prospected.