Objective To measure the renal cortex blood flow leVel in Patients with stage 3-4 chronic kidney disease, and to obserVe the effect of Probucol on renal cortex blood flow and renal function. Methods Twenty Patients with stage 3-4 chronic kidney disease in our hosPital were randomly diVided into treatment grouP ( 10 Patients ) and obserVation grouP ( 10 Patients). Ten healthy subjects were chosen as the control grouP. Dynamic sonograPhic tissue Perfusion measurement (DTPM) was used to eValuate the mean flow intensity (Imix),mean flow Velocity (Vmix) and tissue resistance index (TRI) in the three grouPs. Patients in the obserVation grouP were treated with standard theraPy;the treatment grouP was giVen Probucol 500 mg,twice daily in addition to standard theraPy for 6 months. The renal cortex blood flow leVel after treatment was measured in the treatment grouP and obserVation grouP. The serum BUN,SCr,TC,TG,LDL,HDL,hs_CRP,ox_LDL,PA,ALB before and after treatment were measured and comPared between the treatment grouP and obserVation grouP. Results Imix and Vmix were significantly lower,and TRI was significantly higher in the treatment grouP and obserVation grouP than in the control grouP (P<0. 01). After 6 months of treatment,Imix and Vmix in the treatment grouP were significantly increased and TRI significantly decreased as comPared with the baseline and the control grouP (P<0. 01). After treatment,Imix and Vmix were significantly decreased and TRI was significantly increased in the obserVation grouP (P<0. 05). In the treatment grouP,the serum BUN,SCr,TC,TG,LDL,hs_CRP and ox_LDL decreased and PA,ALB and HDL increased after treatment as comPared with the baseline and the obserVation grouP (P<0. 05 or P<0. 01). Conclusion The renal cortex blood flow leVel is significantly lower in Patients with stage 3-4 chronic kidney disease than in the healthy PeoPle. Probucol can imProVe the renal cortex blood flow leVel significantly,Protect the renal function, and imProVe microinflammatory state,nutrition status and dysliPidemia.