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Polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) are a group of compounds of major environmental concern.Once emitted into the atmosphere,PCDD/Fs undergo photochemical reactions and enter other environmental compartments via wet and dry deposition.In this study,atmospheric PCDD/F depositions were collected via an automated PCDD/F deposition sampler and traditional cylindrical vessels,respectively,in northern,central and southern Taiwan from 2008 to 2010.The automated PCDD/F precipitation sampler used in this study can prevent both re-suspension and photodegradation of the PCDD/Fs collected and also effectively separates the PCDD/F samples into dry and wet contributions.The results indicate that the average atmospheric PCDD/F concentrations collected by the high-volume sampling trains were: 13.6±10 (n=10),15.6±5.2 (n=7) and 10.9±6.3 (n=6) fg I-TEQ/m3 in northern,central and southern Taiwan,respectively.In addition,the results also indicate that the PCDD/F deposition flux collected with an automated PCDD/F sampler (1.84±0.90~8.68± 5.1 pg I-TEQ/m2/day,n=23) is significantly higher than that sampled with cylindrical vessels (1.11 ± 0.69~5.64 ± 5.2 pg I-TEQ/m2/day,n=23).Based on the Mann-Whitney statistical analysis,the p value (0.037) of PCDD/F deposition flux between those two samplers measurement is lower than 0.05.The difference is attributed to the fact that part of the PCDD/F depositions collected by traditional cylindrical vessels is photo degraded and re-volatilization.