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Relay strip intercropping of maize-soybean is the most dominant type of intercropping in China.In this type of intercropping system,the soybean undergoes shade stress from maize over a period of time until the maize is harvested.The shade stress from the maize will considerably influence the seed content of phytochemicals such as anthocyanin,proanthocyanidin and other phenolic during developmental stages of the seed.Therefore,this study was instigated to investigate the effect of shade application on anthocyanin,proathocyanidin and sucrose contents at different seed development stages of two black soybean[Glycine max（L.）Merr.]Varieties.The study comprised two separate trials;maize-soybean relay intercropping and soybean monoculture.The shade treatments in the soybean monoculture trial comprised shade applications at:whole growth stage（SW）,vegetative stage（SV）,reproductive stage（SR）,and no shade（CK）.Anthocyanin,proanthocyanidin and sucrose contents were analyzed from seeds obtained at development stages of full size seed（R6）,physiological maturity（R7）and full maturity,95%pods on the plant are mature（R8）and natural air dry（AD）.Genotype,shade and planting season and their interactions had strong influence on anthocyanin,proanthocyanidin and sucrose accumulation in soybean seeds at the different seed development stages.Among all the shade treatment,relay intercropping（IC）recorded the highest anthocyanin contents in 2017(1.88 mg.g-1)and 2018(1.76 mg.g-1)in AD seeds.In addition,the application of shade increased proanthocyanidin and maximum PA(27.14 mg.g-1)was obtained in SV treatment at R6 stage.The overall best sucrose contents(6.14 mg.g-1in 2017 and 7.04 mg.g-1in 2018)were obtained in soybean seeds harvested at R8 under SV shade treatment.These results suggest that by choosing appropriate soybean genotype and shading,anthocyanin,proanthocyanidin and sucrose accumulation can be increased in black soybean seed.In addition,another experiment was conducted to understand the node position of soybean plant effect on seed composition.Environmental conditions such as light,temperature,and humidity prevailing within the top and bottom node of the soybean plant vary,due to the canopy from the top.The canopy from the top prevent uniform distribution of this environmental conditions especially light until maturity stage of the plant.These prevailing condition allow the seeds at the bottom node undergoes shade stress which affect the seed constituents.In this study,four black soybean（E333,E314,QWT47 and D53）were cultivated on the field.The soybean stem was divided into two equal parts depending on the number of nodes.Uniform seed size at the top and bottom node were harvested at（R6）full-size seed（R7）physiological maturity and（R8）when 95%of the pods on the plant are matured.Anthocyanin,proanthocyanidin,sucrose,oil,protein and metabolite content were determined to identify the changes during seed development stages on different node positions of the soybean plant.Among all the varieties used,E314 accounted for the highest anthocyanin content（2.43mg.g-1）at the top node and at the R8 stage.In addition,the top node increased proanthocyanidin with maximum content（3.14m.g-1）was obtained at the R7stage in E314 cultivar.Sucrose content decline as the seed mature from R6 to R8 with the highest content of（9.77mg.g-1）at the top node and at the R6 stage.Metabolomic analysis of developing seeds at different positions in the canopy suggests that,metabolite in soybean varies from the various nodes and development stages.The metabolic pathway analysis showed that node position influence metabolite including Lysine biosynthesis,Arachidonic acid metabolism,Fatty acid biosynthesis,at the various development stage of the seed.Our results establish node-position and developmental stage variation in soybean seed constituents and provide a new experimental system to identify harvesting period to obtain maximum seed composition.