先前文獻在探討有關三聚氰胺事件時多為分析食安事件之影響因素、政府對於食品安全法規定訂之不足以及探討食安事件對於股價變動之影響。而本研究欲藉由公司財務指的變化來探討食安事件對乳製品產業之影響，因此利用差異中之差異(Difference in Difference, DID)方法，探討在食安事件發生後被爆出有參入三聚氰胺之毒奶粉公司相對於未出問題之奶類公司及豆類公司，其營業收入，營業成本及利潤等三項財務指標為相對上升或相對下降之趨勢。因此將樣本分類為三組，一組以毒奶粉公司作為實驗組，其他兩組以為未出問題奶類公司以及豆類公司作為控制組。 本文以2001年至2011年中國規模以上上市以及非上市公司之追蹤資料(Panel Data)進行分析。實證結果指出，毒奶粉公司相對於未出問題公司在食安事件之後，其營業收入為相對增加，營業成本亦相對增加，而利潤則為相對減少。雖然營業收入之估計結果與預期不相符，但是本研究認為可能與毒奶粉公司在樣本資料當中原先就佔有較高之市場佔有率有關。營業成本之增加，本研究認為與事件發生後法規及監管成本之增加有正向關聯。利潤減少之實證結果與預期相符，說明毒奶粉公司在三聚氰胺事件下，就實證結果而言公司會有虧損之情況發生，代表食安事件對乳製品產業有負面之影響。 / Most of the previous researches of the Melamine Incident focused on analyzing the impact on food safety event, the shortage of the governmental food legislation, and the discussion about the food scandal effect on the enterprises’ stock prices. In this paper, we used the variation of the company’s financial indicator in income statement to observe the impact of the food scandal on the dairy industry. In order to do so, we used the method called “Difference-in-Difference” to estimate the impact on the operating revenues, operating costs and profits of the scandal companies after the food safety scandal broke in 2008. In this study, we set our sample into three groups, the group of the scandal dairy companies as the experimental group, while the group of non-scandal dairy companies and the group of beans companies as the control group. The panel data we used in this paper included listed and unlisted companies in China from 2001 to 2011. The empirical results indicated that after the scandal, in contrast to the non-scandal companies, the operating revenues and the operating costs of the scandal companies were both higher, and the profits were lower. The empirical results of the operating revenues didn't meet the expectation of this paper, we supposed the reason was that the scandal companies had much higher market share comparing to the non-scandal companies. In our opinion, the increase of the operating costs was due to the newly released regulations and supervision costs. At the same time, the decrease of the profits was consistent with our expectation. It meant that after the Melamine incident, the scandal companies would suffered financial losses which proved that the food scandal event would have negative impact on the dairy industry.