This thesis will use the power of balance and the alliance theory from the realism in international relation perspective to analyze the origin of America-Russia Cold War after WW2. The work will also discuss the structural factors of the shaping of America-Russia Cold War, by going through the cognition and attitude of America and Russia after ww2 and it's concrete policies. Moreover, to observe the forming of Cold War by concerning the control factors (elements) of allies and enemies, the current rivals, and the safety choices of the new members. Last but not least, we wish to take a look of the ways of obtaining peace in realism perspective, to see if the true reasons behind the shaping of Cold War-is it the origin rivalrous between America and Russia? Or is it a natural state of seeking for the safety balance?