How to disable dhclient to control the interfaces with NetworkManager?

[Farhad Mohammadi Majd <farhadbenyamin@yahoo.com>]

Hello, I did install Debian GNU/Linux v8.7 through NetInstall option,
during installation I did not select any Desktop Environment for install
on system, only `standard utilities', after finish the installation, I
did use `aptitude' to install xorg, gnome-shell, gnome-session and some
parts of GNOME without recomended packages.

Now anytime on system booting, dhclient automatically connects the
interface to network and I just know to use `ifdown' by root user to
turn off the interface.

I want to disable dhclient to control the interface with NetworkManager
by regular user.

How is this possible?

Sorry for my bad english; Thanks for help.