Objective To investigate the changes of ocular hemodynamics in patients with retinal vein occlussion(RVO). Methods The hemodynamic parameters(PSV,EDV,PI,Vmax)of central retinal artery(CRA)and central retinal vein(CRV)were measured in the involved eyes(n=48) with RVO and the contralateral clinically healthy eyes(n=39) and in the control eyes(n=40) by color Doppler imaging (CDI)(ATLHDI3000). Results Peak systolic velocity (PSV) and end diastolic velocity (EDV) were significantly lower in the CRA of involved eyes and clinically healthy eyes of patients with RVO compared with control eyes,and pulsatility index(PI)was significantly higher in the CRA of involved eyes of patients with RVO compared with control eyes.PSV were significantly lower in the CRA of involved eyes of patients with RVO compared with their clinically healthy eyes.Pulsatility index(PI)was significantly higher in the CRA of involved eyes of patients with RVO compared with their clinically healthy eyes.Maximun vein velocity (Vmax) was significantly lower in the CRV of involved eyes and clinically healthy eyes of patients with RVO compared with control eyes. Conclusion The changes of hemodynamics in CRA,CRV of involved eyes of patients with RVO may invade their clinically healthy eyes.CDI may be helpful to early diagnosis for RVO. (Chin J Ocul Fundus Dis,1998,14:111-113)