Over the last 30 years since 1980’s, General Directorate of Mineral Research & Exploration of Turkey (MTA) and Geological Survey of Japan have conducted international collaborative projects in the field of active fault and paleoseismological studies. Here, we introduce some of the results derived from the projects including on-going researches. The first progress since the initiation of the relationship between two organizations is mapping of the active faults all over the Turkey. The knowledge and technique of mapping of active faults has been exchanged and improved. The first active fault map over Turkey was published in 1992 by MTA at 1:1,000,000 scale. Later, more detailed mapping has been introduced using 1:10,000 scale airphoto interpretations, and now we have obtained renewal maps at 1:250,000 scale all over Turkey. The base maps of mapping were used at 1:25,000, then, they are compiled at 1:250,000 scale. Secondly, the first successful paleoseismic trench in Turkey has been brought under our collaborative project in 1990’s. After the occurrence of the 1999 Izmit and Duzce earthquakes, main purpose has shifted to paleoseismological researches on the North Anatolian fault system. Numerous successful paleoseismological researches have brought the exchange of knowledge and techniques. Now, MTA has already started to lead national project of paleoseismological researches of Turkey for long-term forecast of large earthquakes.