To evaluate the preliminary safety and efficacy of the EXCEL II stent system. Although the first biodegradable polymer drug-eluting stent (BP-DES), EXCEL, was launched nearly a decade ago, in-stent restenosis and stent thrombosis remain pertinent clinical problems in practice. A new cobalt-chromium BP-DES EXCEL II has been developed with the aim of improving stent safety and efficacy. Forty-five patients with single de novo native coronary lesions were enrolled and randomized to two groups in a 2:1 ratio, the 4-month follow-up group (n = 30) and the 12-month follow-up group (n = 15). All patients underwent percutaneous coronary intervention (PCI) with the EXCEL II stent system. Quantitative coronary angiography (QCA) and optical coherence tomography (OCT) were used to assess coronary vasculature at the designated 4- or 12-month follow-up. The primary outcome was major adverse cardiac events (MACE) at 30 days post-PCI. No MACE, thrombotic events, or target lesion failure was found in the 45 patients during the 12-month follow-up. There was no significant difference (P > 0.05) between the two groups in terms of in-stent and in-segment late lumen loss (LLL). No in-stent and in-segment restenosis was found in either group. At follow-up, the ratio of >10% uncovered struts per lesion was 26.67% in the 4-month group and 0% in the 12-month group (P < 0.05). Neointimal coverage in the 12-month group was significantly better than in the 4-month group (98.58% vs. 93.51%, P < 0.01). This first-in-man study demonstrates promising feasibility, safety, and efficacy of EXCEL II stents. These stents were found to have rapid endothelialization and low LLL rates at 4 and 12 months after implantation.