The aim of this paper is to discuss in its preface a variety point of views of Islamic school of thoughts concerning the accurate definition of concept “Khabar al-Wahid ". It will examine the method of Hanafi’s school of thoughts and the method of majority of jurists in terms of providing definition for the previous term. In the first part, it provides a wide range of arguments for and against of believing that employing Khabar al-Wahid as a proof for two kinds of issues in Islamic Sharia. This paper claims that this type of Sunna is an acceptable source for either doctrinal issues or principle ones. It should be emphasizing on the fact that the majority of Muslim scholars believe that this type of Prophetic saying is not strong enough to prove doctrinal issues because such issues need to be built on sacred texts that certainly proves this sense. For the majority, this level of certainty is impossible with this sort of Prophetic tradition. More importantly, we fully convinced that "Khabar al-Wahid" has been practically used by many Islamic scholars to prove doctrinal issues even though they reject this way of understanding conceptually. The second part of this paper has dealt with another related controversial issue which is that "Khabar al-Wahid "should be applied in worshiping context under the belief of obligatory (وجوب العمل بخبر الواحد) or having a choice ((جواز العمل بخبر الواحد. In this context, this paper widely provides arguments for and against. It also gives special attention to discuss weakness and strength of the two sides of these arguments.