Chemical weapons are any chemical agents used to cause intentional death or harm through its toxic character. The impact upon the chemical weapons attack causes not only a physical harm but also psychological consequences and therefore it often causes a greater harm than the impact caused by conventional weapons attack. Regardless the various treaties which reflect the universal agreement on the importance of chemical weapons prohibition, the continued use of chemical weapons without consequences poses an immediate threat to the international peace and stability. Syrian civil war has reflected the horror of repeated use of chemical weapons. This research aims to elaborate the international humanitarian legal perspective upon the continued use of chemical weapons and the obstacles upon the law enforcement of the violations. These issues are solved using normative legal research. The data are collected through statutory approach and case approach. The result of the analysis shows that the parties involved in Syria conflict have violate the principles of international humanitarian law by using chemical weapons in warfare. Moreover, the factor which caused the difficulties in adjudicating the violation is the nature of international law system itself as a soft law which lacks mechanism of compulsive enforcement. Therefore, the research suggest that the Organisation on the Prohibition of Chemical Weapons should be more critical in investigating the chemical weapons in Syria and implement the more suppressive measure to enforce its regulation in eliminating the chemical weapons.