A model of construction of state border protection on the river section has been developed. The model is developed using probability theory approaches. The model is based on the calculation of the capabilities of heterogeneous forces and means to detect and detain violators of the state border. The model is intended for use by the headquarters of the border detachment in preparation for operational and service activities in the next period. The model allows to build effective protection of the river section of the state border, taking into account threats to border security and the capabilities of available forces and means.