A method for acquiring monitoring data and a system thereof, a task distribution server and an agent are disclosed. The method for acquiring the monitoring data includes: receiving registrations of the agent and a gathering device by the task distribution server; receiving, by the task distribution server, an acquiring instruction sent by the gathering device; and sending, by the task distribution server, the acquiring instruction to the agent to instruct the agent to acquire the monitoring data. Hence, a flexibility in acquiring the monitoring data is improved.