Protection of an object consists of several lines, the number of which depends on the level of sensitive sites. In all cases, an important milestone is the system of access control systems (ACS). Well organized with the use of modern means access control allows to solve a number of problems, such as opposition to industrial espionage, protection of confidential information, time tracking, monitoring the arrival and departure of staff. With the implementation of specific ACS uses different methods and implement their devices to identify and authenticate a person. ACS is one of the most developed segments of the security market, both in Russia and abroad. According to some experts annual growth of ACS is more than 25%. The number of professionals working in the field of technical security systems, is more than 500 thousand people. In this article the main objectives and tasks of ACS are formulated, ACS typical structures are shown. A comparative analysis of the various embodiments of the ACS is made, basic guidelines for choosing the means and access control systems are provided. The conclusions about the benefits of implementing access control for enterprise security are reached and the prospects for their development are assessed.