Background : The roots of Curcuma longa Radix is used to make herbal medicine, which is registrated in the Korean Pharmacopoeia. This species is a perennial herb, and is distributed throughout tropical and/or sub tropical regions. High temperature and humidity with small difference between daytime and nighttime is the finest environment condition in this species. Recently, demand for C. longa has been expanded to cultivation area as central region from southern region. Therefore, this study aimed to investigate the effect of harvest time on the growth, yield characteristics and main composition contents in C. longa. Methods and Results : Curcuma longa rhizomes were harvested from farmland in Jindo, Jeollanam-do in end October, early November, middle November, end November, early December, middle December and end December 2015. Harvested rhizome were dried in hot air drier, and it was investigated as growth characteristics and yield. Contents of curcumin, demethoxycurcumin, bisdemethoxycurcumin was analyzed from dried powder of rhizome. The analysis column was used to Phenomenex, Kinetex 2.6um F5 100A 100*2.1mm. 10 mg of standard was taken, 80% MeOH was added to dissolve in 10 ㎖ flask. 0.5, 1, 2, 4 ㎖ was taken from dissolved solution and then was added to 10 ㎖ of 80% MeOH. It was filtered through 0.45 ㎛ filter and then 5 μℓ was taken to make standard solution. Analytical calibration curve was measured to diluted solution within sample concentration. 2 g of ground sample was taken, 40㎖ of 80% MeOH was added to extract by ultrasound sonication during 60 minutes and then it was filtered through 0.2 ㎛ filter to analyze component content. Conclusion : The root weight significantly increased from 376.1 g in end October to 695.9 g in end December as 1.8 double. Curcumin contents differed significantly among harvest times in end November and early December. Demethoxycurcumin increased from early November to end November, and Bisdemethoxycurcumin increased to the early November.