In the red soil region of southern China,the soil acidification is increasingly sharpening and the soil nutrients is getting more impoverished,so the study on the techniques of red soil improvement and corresponding materialized products is very important for yield increasing and the red soil sustainable utilization.Through three years continuous experiment of peanutrape rotation cropping in dry land red soil,the effect of botanical soil conditioners on the red soil microstructure,physic characteristics,nutrient and pH value were researched,moreover,its effects on the yield of peanut and rapeseed were analyzed.The results indicated:1)As for the microstructure,the compaction of red soil declined,the diameter of the soil particle＜4 μm,but the porosity increased after soil conditioners application.2)The bulk density of soil significantly decreased after soil conditioners application,the porosity increased to over 59%,the increased range of big granule water stable aggregate content(>0.25 mm)was 1.6%~14.0%,fractal dimension significantly reduced,and it was significantly and linearly correlated to the content of aggregate structure whose particle diameter was more than 0.25 mm.3)The soil conductivity,the content of organic carbon,mineral nitrogen,available phosphorus and potassium were improved by a range of 4.3%~143.7% after soil conditioners application.4)The red soil acidity was significantly reduced under soil conditioners application.Soil pH value increased from 5.28(CK)to 5.82.5)Soil conditioners application increased the yields of peanut and rapeseed by 13.1%~24.8% and 10.3%~21.6% respectively.6)Based on the above results,it was concluded that the tested soil conditioner could effectively improve the red soil physical and chemical properties and subsequently improve the crops yield,and the optimal application rate was about 2 250~3 000 kg/hm2 on the red soil.