A method of risk monitoring in online business is disclosed. The method captures parameters of a user request and business data of processing the request by a business processing system; packs the parameters and the business data into an event object; analyzes the event object according to risk monitoring rules; and generates a risk record if a risk is determined to exist in an operation event that produces the business data. The method further determines a risk processing mode according to the risk record and a risk processing configuration, and processes the risk of the operation event in the risk processing mode. Also disclosed is a system for risk monitoring in online business.