Environmental components, including animal species, simply cross political boundaries and, in other words, animal species do not recognize borders. For this reason, the most important methods applied by international instruments to protect these species and their habitats are reviewed in this article. In the second half of the 20th century, numerous international texts have been adopted, especially aimed at ensuring the protection of species and habitat of wildlife. The Convention on International Trade in Endangered Species of Wild Fauna and Flora or CITES (also known as the Washington Convention) of1973 is one of the most important international conventions on the protection of animal species. In parallel with these international developments, various national legislative systems have been adopted different regulations for the protection of animal species. The diversity of rules in different countries clearly shows the approach of each State with regard to infringements committed against animals. In Iranian law, as many other countries, several legislative provisions in respect of animal species have been adopted. In this work, we will only address the criminal law as it relates to the Iranian Law of Hunting and Fishing as lex specialis and the Iranian Penal Code as lex generalis. The choice of the provisions mentioned is not by chance since not only are they relatively broad in scope but also they are the laws in force in this area.