1999 Helsinki European Council summit is one of crucial steps in the Turkey-EU relations. Beside other significant points of summit conclusions, Turkey was determined as a candidate state to the EU although it has already been a associated membership. In this context, Turkey, as a candidate state, has begun to make amendments its legal, economical and social life to prepare itselfnegotiations. The amendments in the legal sphere have pretty fast brought its legal order in line with the EU primary and secondary legal sources. This has made and has been making in two main subtitles: Constitutional amendments and legal harmonization.