AIM: To study the early changes of choriodal neovascularization(CNV) after photodynamic therapy (PDT). METHODS: Ten cases（13 eyes） with subfoval CNV suffered PDT using visudyne. The changes of letters of ETDRS (early treatment for diabetic retinopathy study),optical coherence tomography (OCT) and fundus photography before and three days after PDT were compared. Using the software of OCT, the bilaminar foveal thickness (Tf),neuroretinal foveal thickness (Nf),outer high reflectivity band thickness (T) and subretinal fluid thickness (SF) were measured. RESULTS:Ten eyes were found retinal edema while 7 eyes were found increases of subretinal fluid three days after PDT. But CNV had no changes. Only the changes of SF had significant differences（P<0.05）, and increased about 133.38±184.94μm. The letters of ETDRS,Tf,Nf and T had increased but with no significant differences. CONCLUSION: Three days after PDT, OCT showed increases of retinal edema and subretinal fluid of CNV. This maybe the cause of the color vision chaos and decrease of visual acuity early after PDT.