Plan environmental impact assessment (PEIA) is to analyze, forecast and assess the influence that the plan may lead to; it is a kind of strategic environmental assessment. Some high-level PEIAs need to deal with the position and dimension of the construction in the region. The aim of risk assessment in the PEIA and the aim of PEIA should be the same, i.e. to analyze the risk involved in the plan from the source and raise some plans to prevent and reduce the risk. The similarities and difference between risk assessment in construction environmental impact assessment and plan environmental impact assessment were compared. It was pointed out that the aim of risk assessment in PEIA is to identify and analyze the venture source, guide the position and dimension of construction as well as the soil utility in region, and give feedback. The characteristics and the differencebetween assess procedures of risk assessment in PEIA and in construction environment impact were summarized. With the risk assessment in PEIA of Pingdingshan Chemical Industry Park as an example, the applications of risk assessment to planenvironmental assessment were discussed.The result point out that the risk from Chemical Industry Park have some influence on the village around,the action of movement should be considered.