The transitory nonuniform expansion, the so-called dogboning, of stent/balloon system is one of the main reasons to induce the acute vascular injury at the two edges of a stent. This kind of vascular injury has a close relationship with the in-stent restenosis. The purpuse of this study was to evaluate the relationship of dogboning phenomenon and lesion morphology in real world DES implntation. Methods: IVUS image was acquired in 89 patients after DES implantation with norminal pressure. Quantitative and qualitative analyses were performed. Dogboning was defiend as: Dogboning = (Maimum stent area of edge - minimum stent area of mid one third portion of stent)/minimum stent area of mid one third portion of stent ��� 100. Results: Preintervention lesion maximum calcium arch (r=0.384, p<0.001), calcium length (r=0.234, p=0.03), remodeling index (r=0.219, p=0.04) were related to degree of dogboning but plaque burden (r=0.199, p=0.07), lesion length (r=0.68, p=0.53), minimun lumen area (r=0.86, p=0.43) were no significant relation with dogboning. Conclusions: Maximum calcium arch (r=0.384, p<0.001), calcium length (r=0.234, p=0.03), remodeling index (r=0.219, p=0.04) are predictor of nonuniform expansion of DES and consider adjuvant balloon dilatation in these kind of lesions.