Abstract: In order to understand the rules and characteristics of arsenic uptake from garlic, peanut different tissue under arsenic solution stress, and to establish a rapid determination method of arsenic in agricultural products, microwave digestion procedure was used to process samples rapidly, As5+ was changed into As3+ in the digestion solution. According to Faraday's law of electrolysis, anode electric I3-was determined, the mass fraction of arsenic in sample was calculated according to the power consumption directly. The results showed that:the samples from surface to inside. All tissue absorbs arsenic, the average absorption of garlic was 7.363~6.281 mg/kg, the average absorption of peanut was 7.191~1.083 mg/kg. This method was reproducible, simple, fast, and suitable for rapid analysis of elements arsenic in agricultural product . Garlic powder parallel was determined 12 times and its RSD was 3.2%(n=12), the recovery rate was 98.80%~102.80%.