By the representative field sampling investigation and laboratory analysis

the classification and evaluation of depredated Robinia pseudoacacia plantation in the Yellow River Delta region were studied based on the 14 indexes of tree morphology(tree height

diameter at breast height

timber volume

canopy density) and soil physicochemical property(soil bulk density

soil porosity

organic matter

initial infiltration rate

stable infiltration rate

pH value

and salt content).Results indicated that the tree age of R.pseudoacacia plantation in the region was relatively single.The low quality and low-benefit classificatory criteria only by forest growth procedure and structure were unsuitable for the depredated R.pseudoacacia plantation in the region.The classification and evaluation of R.pseudoacacia plantation should combine the forest growth indexes with soil physicochemical properties.Principal component analysis showed that the main factors affecting the low-quality and low-benefit R.pseudoacacia plantation were in the order of soil bulk density soil porosity forest canopy density timber volume soil organic matter salt content.Cluster analysis indicated that the R.pseudoacacia plantation could be classified as the five types of potential type

slightly low-benefit type

medially low-quality and low-benefit type

extremely low-quality and low-benefit type

and badly low-quality and low-benefit type.According to the mean cluster value

the main features of the different types of forest

causes for the low-quality and low-benefit forest

and management measures were all evaluated.