Harmful elements and certain trace elements in foods will endanger human health. The margin of safety to some trace elements is very narrow. Excessive intake or lack of certain trace elements all will cause problem to human health. Element forms is divided into physical form and chemical form. Physical form refers to the physical state of an element in a sample; Chemical form refers to the presence of an element in the ion form or molecular form. In food, the toxicity of certain elements is not only related to their total amount, the contact time, but also realted to their chemical form. The recent research advances of arsenic, mercury, lead and selenium on food safety were reviewed. The sources and forms of 4 elements in food and their effects on toxicity, their toxic mechanisms and safety control as well as unsolved problems in the filed were summarized. The paper provides a reference for further research on arsenic, mercury, lead and selenium in the area of food safety, toxic material dynamics study, evaluation of food safety, and pollution prevention and control.