This dissertation is an attempt to find better solutions for the piracy problem in the 21 century by improving the international and domestic law legal regime. First chapter introduces piratical activity and legislation in ancient time, and briefly discusses the development of piracy law. In the second chapter, an in depth sociology and economic study on the modern piracy and counter-piracy measures is conducted, which leads to the findings that modern piracy has developed new features and legislation improvement has superior advantages as a long term solution. Then this dissertation continues to analyze the international law on piracy in third chapter. By examining the international laws under current piracy circumstance, the deficiencies of international law regime are brought up. In the fourth chapter, the comparative law study on domestic criminal law of countries that have actively engaged in piracy prosecution or legislation. The piracy adjudication practice and discrepancies in domestic law further reveals the problem with the international law. The fifth chapter discusses the deficiency of domestic maritime law in face of modern piracy. Based on the analysis in the first five chapters, this dissertation raises two methods to improve current piracy law regime in the final chapter.