Taking ‘Xianjiaowang’ pepper as test material and by potted culture method，this paper
explored the main root system in phosphorus（P）high efficient utilization and rhizosphere process through
analyzing the changes in mophology and physiology of pepper root system under different phosphorus
application levels．The results showed that the biomass of pepper overground part and root system increased
firstly then decreased with the increase of P application．Along with the increase of P supply，the total root
length showed a tendency of first increase then decrease，and the average root diameter and ratio of root to
shoot decreased gradually．The rate of arbuscular mycorrhizal colonization and activity of soil acid phosphatase
in pepper root system increased firstly then decreased．The correlation analysis showed that soil Olsen-P
concentration and whole plant P concentration were extreme significant negatively correlated with average root
system diameter，and root arbuscular mycorrhizal colonization；and could be fitting with the total root length
by quadratic equation with one unknown，indicating that the rhizosphere trait of pepper root system adapted to
low P might be achieved by increasing root biomass and total root length，while reducing the average diameter
of root system．