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Recent studies have indicated that the observed nitric acid (HNO 3 ) uptake rates (R HNO 3 ) onto dust particles are much slower than R HNO 3 used in the previous modeling studies. Three factors that possibly affect R HNO 3 onto dust particles are discussed in this study:(1) the magnitude of reaction probability of HNO 3 (γ HNO 3 ), (2) aerosol surface areas, and (3) gas-phase HNO 3 mixing ratio. Through the discussion presented here, it is shown that the use of accurate γ HNO 3 is of primary importance. We suggest that the use of γ HNO 3 values between ~10-3 and ~10 -5 produces more realistic results than the use of γ HNO 3 values betweeñ 10 -1 and ~10 -2 does, more accurately modeling the nitrate formation characteristics on/in dust particles. We also discuss two different types of aerosol surface area, active and geometric, since the use of different aerosol surface areas often leads to an erroneous result in R HNO 3 . In addition, the levels of the gas-phase HNO 3 are investigated with the example cases of TRACE-P DC-8 flights in East Asia. The HNO 3 levels were found to be relatively high, indicating that they can not limit nitrate formation in dust particles.