Global Navigation Satellite System (GNSS) is the most popular technique in the area of navigation and positioning,due to its performance is satisfied for most applications in the open‐sky environment.However,GNSS always fail to provide satisfactory performance due to signal blockage in some environments such as urban terrain,forests or indoor scenarios.The traditional method to resolve the above problem is to develop various augmented systems,or build some terrestrial‐based wireless positioning system,working together with GNSS or independently.Cooperative positioning is a new paradigm around how devices can cooperate with each other to improve their ability to compute position,compared to traditional augmented methods,it does not required a fixed infrastructure,and even provide a better performance.Cooperative positioning is an effective way to improve the performance of positioning accuracy,availability,etc.The positioning accuracy is a fundamental metric for positioning system.In this contribution,we discuss the two expressions of Cramér‐Rao Bound (CRB) on positioning accuracy,and the relationship between them.Meanwhile,we prove the conclusion that the fundamental positioning performance in cooperative positioning outperforms that in traditional (non‐cooperative) positioning,rather than verification via numerical simulation.