In order to solve the problem of stem curve of herbaceous peony cut flowers in cultivation, three varieties: Huangjinlun,Yinxianxiuhongpao and Zifengchaoyang were used in the research as plant materials to study the effect of different forms and concentration of Ca2+. Altogether four different Ca2+ treatments were arranged during the pre-harvest stage: 2% CaCl2 and (CH3COO)2Ca, 4% CaCl2 and (CH3COO)2Ca. Besides, principal component analysis was used to evaluate the different treatments synthetically. The results showed that: organic Ca2+ was superior to inorganic Ca2+; the best concentration of (CH3COO)2Ca was 4%; the effect of spraying Ca2+ to the stem quality of herbaceous peony showed obvious differences among the three varieties. With 4%(CH3COO)2Ca, the stem quality of Huangjinlun and Yinxianxiuhongpao could be improved a lot while the calcium treatment was unsuited to Zifengchaoyang.