Abstract: In order to find out the influence of the percentage of doping concentration of core surround on transmission characteristics in photonic band gap photonic crystal fibers(PBG-PCF), simulations on 7-cell PBG-PCF core surround doping and 19-cell PBG-PCF core surround doping were carried out by using full-vector finite element method under the condition of the percentage of doping concentration between 1% and 5%. The core-confined energy of these two structures were compared, and the influence of the percentage of doping concentration on optical fiber transmission characteristics in 19-cell PBG-PCF was investigated, such as the distribution curves of bandwidth, dispersion, effective mode area and effective mode index in different the percentage of doping concentration. The results show that the light limiting capacity of 19-cell PBG-PCF is better than that of 7-cell PBG-PCF, and the percentage of doping concentration has notable influence on optical fiber transmission characteristics.