A method and a system of distinguishing between a human and a machine are disclosed. The method includes: when a request for accessing a designated network service is received, recording information of the request which include a time of receiving the request and information of an access object that sends the request; computing a statistical value of requests sent by the access object in real time based on a record; and determining the access object to be abnormal when the statistical value of the requests sent by the access object falls outside a predetermined normal range. The disclosed system of distinguishing between a human and a machine includes a recording module, a computation module and a determination module. Identification between humans and machines using the disclosed scheme is difficult to be cracked down and can improve an accuracy rate of human-machine identification.