Abstract: To study the relationship between floral organ development period and effective component content of Lonicera japonica, samples at five different developmental stages of L. japonica were collected and analyzed for the content, accumulative amount and ratio of chlorogenic acid, caffeic acid, luteolin, isopropenic acid A, chloro?genic acid B and isochromatic acid C by HPLC method. The results showed that: (1) the contents of chlorogenic acid, caffeic acid, mignonette glycosides and isochlorogenic acid A were the highest in green bud period, respec?tively reached 27.29, 0.22, 0.84, 0.36 mg/g, but the peak content of isochlorogenic acid B, isochlorogenic acid C and total isochlorogenic acid appeared in the infant stage, they were respectively 7.22, 1.77, 9.30 mg/g; (2) the cumulant of chlorogenic acid, caffeic acid, isochlorogenic acid A, isochlorogenic acid B, isochlorogenic acid C and the total isochlorogenic acid were the highest in white bud period, they were respectively 82.19, 4.12, 5.56, 101.67, 23.05, 130.07 μg/bloom; however the maximum cumulant of mignonette glycosides appeared in the green bud stage (10.39 μg/bloom); (3) with the development of floral organ, the ratio of chlorogenic acid and mi? gnonette glycosides decreased first and then increased, the ratio of isochlorogenic acid A increased, while the ra?tio of isochlorogenic acid B and C reduced. In conclusion, the effective components’content, accumulation amount and proportion of L. japonica are closely related to its development period, and the optimal harvest time is white bud stage.