This study aimed to evaluate the effect of two calcium formulas (CaCl2 and CaH4O8P2) at 0.4 and 0.8% on physical and chemical changes to Chiang Mai Pink patumma. The evaluation which included a comparison with control, included an assessment of weight loss, water absorption, bract color, polyphenol oxidase (PPO) activity, phenolic content, browning incidence and vase life. A completely randomized design was arranged with five treatments: CaCl₂ 0.4%, CaCl₂ 0.8%, CaH₄O₈P₂ 0.4%, CaH₄O₈P₂ 0.8% compared with control. The experiment was carried from May to July 2010 with four replications and ten flowers per replication. The results showed that treating with both calcium solutions (CaH₄O₈P₂ 0.4%, CaH₄O₈P₂ 0.8%) led the flowering stem to absorb less water. At 0.8% CaH₄O₈P₂caused maximal bract color in terms of a* and b*, highest phenolic content and browning severity. These above characteristics brought about the shortest vase life (7.60 days). The Control flower was found to have minimum PPO activity, phenolic substance and browning damage. Thus, applications of CaCl₂ and CaH₄O₈P₂ at 0.4 and 0.8% were found to be not the appropriate substances for maintaining the quality and prolonging the vase life of the patumma's flower. © 2012 Academic Journals Inc.