Provided are a system and a method for monitoring a web service. The web service monitoring system includes a management module configured to provide an interface for receiving an test scenario and a policy for a simulation test of a target system from an administrator and outputting the simulation test result of the target system to the administrator, a database configured to store the received policy and test scenario, and an agent configured to access the target system according to the test scenario and the policy stored in the database and carry out the simulation test of the target system.