Toxicology,as an emerging interdisciplinary subject,has a profound impact on every individual,from food safety to drug safety,from biological safety to ecological safety.Every day,human beings are creating new chemicals,including pesticides,industrial chemicals,food additives,medicines and so on.These new chemicals need clear toxicity assessment and exposure based risk assessment conclusions before they are put into use.Because some preclinical and clinical trials are too hasty and toxicology is not systematically studied,many safety problems of new drugs are constantly emerging in clinical application,resulting in many serious drug hazards worldwide.