[en] In order to evaluate the effect of restraint of Pressure Induced Bending(PIB) on leakage-size-crack in LBB evaluation, this study calculated Crack Mouth Opening Displacement (CMOD) for circumferential through-wall crack in pipe by using both elastic and elastic-plastic finite element analyses. The analyses results showed the restraint of PIB was decreased crack opening for a given crack size and tensile stress, and the effect was considerable for large crack and short restraint length. Also, the restraint effect of CMOD was independent on the variation in pipe diameter and decreased with increasing pipe thickness, and it depended on not total restraint length but a restraint length near the crack for non-symmetrically restrained condition. Additionally, the effect of restraint of PIB was more significant in the results of elastic-plastic analysis compared with that of elastic analysis. On the other hand, the estimation of the PIB restraint effect on the pipes which have been appled LBB showed that the effect on the LBB application is negligible in these pipes