Soybean plants with different abilities to use phosphorus have varying root traits. A study looked at how phosphorus levels affect taproot length, root/shoot ratio, root volume, root activity, and specific root area in two soybean cultivars. Results showed that at different growth stages, the relationship between root traits and phosphorus levels was complex. Phosphorus-efficient soybean plants had longer taproots and higher root/shoot ratios at the seedling stage. However, at the branching stage, taproot length did not differ significantly between efficient and inefficient plants. By the blooming stage, efficient plants had longer taproots and higher root/shoot ratios again. And at the podding stage, efficient plants had higher root activity and root volume under certain phosphorus levels.