Abstract: Division propagation is one of the main breeding methods for peony. Bud number of the divided plants plays an important role on the growth of peony. To provide a theoretical basis for peony separated plants with different numbers of buds, the growth and photosynthetic characteristic of peony cultivar ‘Sarah Bernhardt’ were studied. These plants were divided into three levels according to their bud numbers: more than 5 buds on per root was the first level; 3 to 4 buds was the second level; and 1–2 buds belonged to the third level. The results showed that plants divided in the second level grew best with the widest stems and crown ranges. The net photosynthetic rate(Pn) was also the highest. The light compensation point(LCP) and light saturation point(LSP) were 21 and 1 056 µmol/(m2•s) respectively. As to the content of chlorophyll(chla, chlb), chla/chlb of plants in the second level was in the highest and the values of chla, chlb, chla+chlb were also higher than other levels.