Analysis the principle of reasonableness of governmental decisions in England and Iran's legal system

Judicial review on administrative regulations is the great implement of administrative law for guaranty the legality of administrative decisions and courts apply various principles to diminish public authorities offense in decision-making process. In this paper, reviewing the British legal system indicative that common law courts by apply effective principles , play considerable role in upgrade government’s responsibility and ensuring the fundamental Human Rights .One of this principles is the reasonableness of governmental decisions that according to this principle , the public authority should consider relevant considerations in decision-making process and leaving aside the personal and party interests.In addition ,alongside the analyze the concept of reasonableness principle in British legal system , we study the Administrative Justice Court’s judgments and perceive that we can see footprint of apply this principle by the Iranian administrative judge .Yet , this issue demonstrate that there is a legal loss in controlling the discretionary powers of public authorities in our legal system and we think this problem requires legal reforms and governance the public law’s principles in the judge’s approach at Administrative Justice Court .