【Objective】The objective of this study was to investigate the influence of fibrous and taproot plant root exudates, in terms of their relative composition and application rate, on soil penetration resistance (SPR) under specific compaction conditions (compaction, and compaction followed by wetting/drying), in order to evaluate the adverse effects of SPR on crop growth in clayey red soil.【Method】Fibrous root vetiver and taproot lucerne were selected to collect hydroponic secretions. These secretions were then analyzed to determine the root exudate composition, which was subsequently freeze-dried to obtain the original dry exudates. Clayey red soils (0～20 cm) were amended with different rates of dry root exudate materials (0, 0.02, 0.2, and 1 mg·g^-1, dry root exudates wt/soil wt), and left to equilibrate for one week in a 4℃ refrigerator. Soils amended with varying rates of dry root exudates were then compacted into steel cores (d= 5 cm and h= 5.1 cm) and subjected to two types of compaction. One subset of core samples was wetted to -33 kPa and compacted to 200 kPa stress (compaction), and another subset underwent 200 kPa stress followed by one cycle of saturation and drainage back to -33 kPa (compaction+w/d). The SPR, soil water content (SWC), aggregate properties, and bulk density (Bd) were determined. 【Result】 The results showed that: (1) The relative content of aromatic carbon, alkoxy carbon, and carbonyl carbon in the root exudates was higher in lucerne (3.23%, 6.83%, 55.09%) than that in vetiver (1.64%, 4.12%, 45.78%), whereas the ratio of hydrophobic to hydrophilic substances showed an opposite trend(0.52 for Lucerne and 0.86 for vetiver). (2) The SPR decreased as the exudate rate increased, with a significant decrease observed only when the root exudate application rate exceeded 0.2 mg·g^-1. For example, compared to the control, 0.2 mg·g^-1root exudates application from lucerne and vetiver resulted in reductions of 29.4% and 11.4% in SPR, respectively. (3) At the same root exudate application rate, lucerne showed a higher degree of SPR reduction than vetiver under both compaction conditions. (4) The SWC increased with increasing exudate rate compared to the control. For example, compared to the control, the application of 1 mg·g^-1root exudates resulted in an increase in SWC by 7.98% (compaction) and 21.65% (compaction + w/d) for lucerne, and 13.07% (compaction) and 11.15% (compaction + w/d) for vetiver. Furthermore, the aggregate mean weight diameter (MWD) also increased after root exudate treatments compared to the control. Correlation and regression analysis confirmed that a low ratio of hydrophobic to hydrophilic substances, a high proportion of alkoxy carbon, and a high exudate rate resulted in a low SPR value by improving SWC and aggregate MWD. 【Conclusion】In conclusion, taproot plants showed a more apparent effect in alleviating SPR than fibrous roots in clayey red soil. Therefore, selecting appropriate taproot green manure has the potential to effectively reduce SPR in clay red soil by improving SWC and aggregate MWD.