and earliest from 2 PM by applying 1000 ppm ethephon (Table1). The treated petal of greenish yellow stage released strong smell in cooperation with blooming in advance. Besides, high concentration of ethephon induced enormously open of flower petal (Figure 1) that similar to the response of ethylene in leaf epinasty (Ursin and Bradford, 1989). Nevertheless, this acceleration was ineffective for early-mature (dark green) stage and 1-MCP could exterminate the effect of ethephon (Table 1). Thus, the stage of floral development in Kradang Nga Chin showed different response to various ethylene concentrations. This phenomenon resembles the ripening behavior of climacteric fruit which ethylene can trigger the ripening process in mature green fruit. Therefore, from our results, we can conclude that the blooming and scenting of Kradang Nga Chin flower was similar to those ripening of climacteric fruit.