Objective: To provide basis for safe application of pesticide in Loincerae Japonicae Flos through a dietary risk assessment based on data from the field experiment of deltamethrin. Method: Field experiments were performed by simulating actual field productions to obtain deltamethrin residue data. A risk assessment was carried out based on the dietary exposure and the maximum residue limits. Result: Based on dietary exposure

acceptable adily intake(ADI) and actlte reference dose(ARfD) were much less than 100%

indicting no unacceptable dietary risk. Based on MRL

residue of deltamethrin is lower than MRL in all of tea drinks after pesticide application

and lower than MRL in domestic and foreign herbs and other foods after regular pesticide application

but higher than MRL in domestic and foreign herbs and other foods after irregular pesticide application. Conclusion: On the basis of the two risk assessments

there is no dietary risk in deltamethrin after regular pesticide application. However

in case of increase in pesticide dose and application frequency

the harvest intervals shall be prolonged to avoid risk. This study provides data support for safe application standards for deltamethrin in Loincerae Japonicae Flos and establishment of MRL standards.