This investigation to start in 2006-2008 in February to carry out the central area five counties & cities sanitation bureau to examine the class union division of labor examination, by food sanitation division's examiners of Taichung City, Nantou County, Miaoli County, Zhanghua County and Taichung county to the sell spot check to various of food, by way of the low temperature delivers to the Taichung City sanitation bureau carries on the preservative examination, this inspection method rests on of preservative inspection procedure the Executive Yuan health bureau announcement, altogether examines the benzoic acid, the sorbic acid and the dehydration acetic acid three kind of ingredients, receives specimens total 5,596 from February to December. The examination result showed that, picks out number of articles altogether1955, picking out rate is 35%, further analyzes various counties & cities to deliver examines the situation, Miaoli County picking out rate 47% the highest, Taichung county picking out rate 26% the lowest, it picks out the ingredient to eliminate Miaoli County to pick out the benzoic acid to be in the majority, other county cities all take pick out the sorbic acid as many, analyzes each month to deliver examines the quantity and examines the output, discovered 9-11 month quantity is biggest. Whole year delivers examines food type, various counties & cities delivers examines the most respectively is Taichung City rice wet product 501 and the Taichung rice wet product 341, Miaoli County rice wet product 223. Zhanghua County rice wet product 256. Nantou County rice wet product 194, ,. Five counties cities deliver examine the result, the sorbic acid pick out by rice wet product 317. most, next for bean product 302, the benzoic acid are most by pickled vegetables 289, next for bean product 95, dehydration acetic acid 24 all for rice wet product. The analysis picks out the density scope, sorbic acid 776 is 0.11-1.0 g/kg most, next 168 are 1.01-2.0 g/kg, the benzoic acid is 519 0.11-1.0 g/kg are most, next is 170 1.01-2.0g/kg, dehydration acetic acid 22 is 0.11-1.0 g/kg, next is 5 0.01-0.10 g/kg. Comprehensive survey this investigation result, Miaoli County not qualified rate highest 17% (161/964), Taichung county not qualified rate lowest 6% (88/1528), five counties cities not qualified rate is 10% (504/5596), depends on food type to classify in addition looked, pickled vegetables not qualified rate highest 28%(130/468), rice wet product next 11% (168/1515), baking food to be lowest 6% (24/414).