The invention discloses a flow statistic method based on application, a BRAS and a network. The flow statistic method includes the steps that the BRAS carries out flow statistic on a user with the application used by the user as a unit; the BRAS sends the flow statistic information to a charging server, and the charging server carries out charging on the application. By means of the flow statistic method based on the application, the BRAS and the network, the application can serve as the unit, flow statistic is carried out according to the assigned application, flow charging is achieved, parallel charging based on the user state and application streaming flow can be achieved, and the flexibility and the accuracy of broadband user flow charging are improved.