Spatial data is one of the fundamental parts of GIS.Uncertainty of spatial data can directly affect the quality of digital products and reliability of GIS based decision making and is regarded as one of the fundamental theoretical research issues.In recent years

positional uncertainty of line segments is a research focus.Several models have been presented by other scholars

for example ε band

e band

g band

and H band.Among these existing models

the ε band has been widely used due to its advantage of fixed band width.But it is difficult to determine the band width

which limits its further application.In this paper

we expand the model of H band in literature and present an uncertainty band of average entropy based on average information entropy of the whole line segment.The new model absorbs the strongpoint of ε band and at the same time takes the asymmetry of error distribution in line segment into consideration.It is a comparatively suitable measurement index of the positional uncertainty of line segments.