Abstract: This cross-cultural study between China and the U.S. examined how people's perceptions of environmental risk, preferences in risk management, and perspectives of participatory decision processes and quality vary within the different social, cultural, and political systems. A structural equation model (SEM) with social trust, social value, and risk experience was constructed to explore social processes of environmental risk perceptions and preferences in risk management. A 2'2 experiment with four decision scenarios was designed to examine people's perspectives of successful participatory decision processes and quality. College students from The Ohio State University (n=240) in the U.S. and Beijing Normal University (n=280) in China were participants in the research. The results indicated that both the Americans and Chinese considered that good decision quality depends on effective public input in the decision, good participation process and outcome, and outcome was thought to be the most important factor to affect their evaluation of the decision quality. The Chinese were more concerned about environmental risks, and they perceived the environmental issues to be more risky to health, to the environment, and to economic development in China than Americans. Both groups were less likely to support the policies that require them to participate financially, such as paying increased taxes on gasoline. The respondents from the two cultures desired transparent communication processes and were more likely to support educational strategies to help people change behavior to reduce environment. However, there were significant differences between the Chinese and Americans about support for or opposition to a specific risk management strategy. For the structural equation model, the American data showed that social trust, social value, and risk experience had significant impacts on perception of environmental risks, and risk experience, social value, and risk perception significantly impacted preferences in risk management for the American data. The Chinese data indicated that social value and risk experience had significant impacts on risk perception and social trust predicted preference in risk management significantly. The differences between the two nations about perception of environmental risks, preference in risk management, and decision quality were discussed in political systems, cultural origins, and social reality and situations.