Quote: "i saw the new game engine called xna make by microsoft and i am thinking of using it for making commercial games. Does microsoft allow me to sell my games i make and publish them? "
XNA is not an engine, but a cross-platform API for managed languages (right now only C# is officially supported) to develop applications on both the xbox 360 and windows operating systems without having to program platform specifics.
Basically code you make for Windows, will compile and run on the Xbox 360 without having to change anything. In traditional native programming you have to develop quite a number of changes to get a program to run on multiple platforms. XNA is Microsoft's effort to eliminate this.
You still have to program your OWN engine with it as it is an API, to directly control hardware through the platform OS; rather than an engine created for the specific task of making a game.
There is TorqueX, which is the Torque game engine built-on the XNA Framework.
Currently no you may not sell XNA games, nor are you allowed to publish only release binaries. You may only share games via source although you may release with a pre-built runtime for Windows.
The Commercial version due later this year, will have these restrictions lifted.