Objective: Dynamic differences of synephrine content from same plant of cirtus peel were studied by comparison of production area in different growth period

to explain the multi-function scientific intension of Pericarpium Citri Reticulatae (PCR) and Pericarpium Citri Retieulatae Viride (PCRV)

which provides the scientific basis. It will provide a basis for the improvement of the quality control standards by dynamic accumulation relationship by picking time and effective component. Method: Synephrine content from 45 batchs of cirtus peel which is of four different habitats and different harvest time was determined by reverse-phase HPLC method. Result: The experimental results showed that synephrine content of citrus peel from same plant of four origin in different growth period was reduced with the increasing maturity of the fruit; synephrine content tends to be stable after samples collected in November; synephrine content of citrus peel from the same plant and the same growth period in different years had no significant differences. Conclusion: Different harvesting period exerts a great impact on the flavonoids content in PCR and PCRV. Citrus immature fruit is in the highest content of synephrine

synephrine content of citrus peel in different growth period decreases with increasing fruit maturity.