Abstract: Patumma flower is one of the new exported cut flower that faces with the poor vase life affecting to this flower’s price after cutting. Effects of true flower thinning in conjunction with 1-MCP fumigation at 0, 100 and 300 ppb on postharvest changes and vase life of patumma flower 'Chiang Mai Pink' was studied at ambient conditions (27°C, 91% RH). A Factorial in Completely Randomized Design was arranged with two factors: flower thinning and 1-MCP concentrations. The experiment was conducted from May-September 2011 with four replications and ten flowers per replication. Flowering weight loss, water uptake, bract color and vase life were recorded every other day. The results showed that treatments with true flower thinning, irrespective of 1-MCP application, caused the least flowering weight loss and maintained the highest bract color in terms of L* and a*. In addition, deflowered flowers with no treatments with 1-MCP had maximal vase life of 20.10 days.