Desertion is the absence of a military without the permission of his immediate superior, at a place and time determined by the service, to flee from unity and to leave the army, or to go out, to escape without permission. Military criminal law is a collection of criminal regulations containing orders and prohibitions to enforce law and order and if such orders and prohibitions are not adhered to, then threatened with criminal punishment. Military crime is an offense committed by the legal subjects of the military. In the criminal law the military recognizes two forms of criminal offense that are pure military crimes (zuiver militaire delict) and a mixed military crime (germengde militaire delict). The crime of desertion is a crime specifically committed by a military because it is unlawful and contrary to the law, especially the criminal law of the military. The purpose of this study is to find out how the application of military law against the perpetrators of criminal acts Desertion and how the relationship between the Book of Criminal Law Military with the Book of Criminal Law. With the normative juridical method it is concluded that: (1) that the application of military law to the perpetrators of desertion as military members (TNI) the threat of punishment is more severe than the punishment contained in the Criminal Code (view of lack of sense of justice); Because the army is armed in order to maintain the security; Precisely used Desertion, (2) that the relationship between The law on military criminal law with the Criminal Code, a relationship that cannot be separated because The law on military criminal law is part of the Criminal Code; The Criminal Code applies to everyone thus for the military (TNI) the Criminal Code applies, and for the military (TNI) who commits the crime of desertion will be treated / applied a special rule namely the Criminal Code, this is a deviation from the Criminal Code. Keywords: military law, TNI, desertion crime