This paper deals with using remote sensing to make an overall inventory on the three principal types or low prouucave sous （salinized soils

sandy sous and caicic concretion black soils） in Heaug-Huai-Hai plain

the largest plain in China. The inventory was conducted mainly on the base of the LANDSAT MSS

imageried in the spring and some in other periods after a treaanent ot optical enhancement. The visual interpretation was done in the synthetic analysis methods based on the imayery mechanism combined with the geoscientific regularities

the interpretation results were transformed to a 1:500000 topographic map and the map of low proauctive soiis distributed in Huang-Huai-Hai plain was fairly drawn with the same scale.For the more accurate discrimination of various low productive soils and reduce the blindness and errors in the visual interpretation process

several methods for automatic discrimination and classificaaon were preliminarily found oue

As a result

the problem that in some sectors of Fengqin

Henan province where sandy soils were often confused with the saiinized soils was well solved

the efficiency of automatic classification by computer was improved

the statistical data of low productive soils in three selected sectors were satisfactoryly picked up and a low productive soil distribution map with the pixel as the smallest unit was printed out.