The rules of the due process are applied to administrative proceedings; one of these rules is the legality principle, it indicates that the conduct should be previously stipulated in the norm in order to can be possible to declare the responsibility. However, the administrative penalty environmental proceedings regulated by the Law 1333 of 2009 has established some limits to the application of rules of due process, for example, the presumption of intentionality or negligence how a restriction of innocence presumption and the normative sending how a restriction to the legality principle. This article will analyze if the restrictive application of legality principle enshrined in the article 5 of Law 1339 of 2009 is adjusted to the demands of reasonableness, purpose and proportionality, and therefore, that results accord to National Constitution.