Purpose:To evaluated and analysis the magnitude and induration of edema after permanent 125I seed brachytherapy with the guidance of individual digital template in the parotid gland and to investigate the effect on the dosimetry delivered by the implant.Material and method:12 patients treated with 125I seed who had three postimplant CT scans were selected for the study.the post-implant CTs were taken on day 0 and 2months and 4months.the guidance technical of CT or/ and digital individual template were used to insure the accuracy of implantation with 125I prescribed to 100-120Gy.The magnitude and duration of edema were determined from the change of volume of the head and neck CT slices selected, which was calculated by the skull volume minus the throat volume.A dose-volume histogram was compiled for each postimplant CT scan.The V 100 ,V 90and D 100, D 90 from the first, second and third post-implant CT scans were compiled to determine the effect of edema on these parameters.the edema associated factors were also analysed with univariate Tests.Results: The magnitudeoftheedema,expressed astheratioofthepost-to pre-implantvolumeonthe day of the procedure,ranged from1.01 to 1.27(mean 1.08).The edema decreased to the pre-implant level 2 months later(1.009 ±0.077) and decline alittle in 4ms CT scans(0.979±0.076).as the edema resolved, the dosimetric parameters V100 and D90 increased in all patients with the range 4.3±3.0 % and 11.2±1.1% between the first and second post-implant CT.slight change were experienced between the second and third CT(0.78±1.8 and 1.8±4.5).The sum of needles effect the edema more significantly(p=0.007, observed power=0.865).The male patientsdeclined to have more sever edema(p=0.006, observed power=0.883).Conclusion:In the parotid gland cancer patients who received the 125I brachytherapy under with the digital individual template guidence, Post-implant edema increased from 1.01 to 1.27(mean 1.08).and resolved two months after implantion.Edema had a significant effect on the post-implant dosimetry of V 100 and D 90 which increase 4.3±3.0 % and 11.2±1.1% between the first and second post-implant CT..The dosemetric of first CT(2ms post-implant)could be used as a more reliable result to evaluate the quality of the implant ,as the V 100 and D 90 approaching the pre-implant plan and slight change between the second and third CT.a large number of cases are still needed to investigate the correlation between the edema resolve and dosemetric change.