The SKA (Square Kilometer Array) is a next-generation radio telescope consisting of 3000 antennas, planned by an international organization. The SKA has an unprecedentedly wide field, wide frequency coverage, high sensitivity, and high angular resolution simultaneously at 100 MHz-10GHz. It will allow us to probe the Universe at a level of sensitivity and completeness orders of magnitude beyond what has previously been achieved, targeting scientific themes from cosmology to extragalactic life. In 2012, a significant progress has been made for the SKA, including the final decision of the sites of the SKA. Also, the international SKA science working groups were reorganized, and the scientific activity of the SKA is just starting in a unified way. In East-Asia, we had an East Asia SKA Workshop 2011 and made a kick-off discussion to have efficient collaborations among East-Asian countries both in scientific and engineering sides. Now in 2013, we organize an SKA Science Workshop in East-Asia. The aim of this workshop is to put together the scientific efforts in various fields of astrophysics from East-Asia as well as other countries. Plenary review talks, oral and poster presentations are planned. We also take significant time for a deep scientific discussion for each field of astrophysics so that we can produce new scientific proposals. Given that the SKA will have been a major radio telescope in the next decade, we encourage young researchers including PhD students to come and join the workshop. This Workshop is supported by Leadership Development Program for Space Exploration and Research, and the Kobayashi Maskawa Institute for the origin of particles and the universe, Nagoya University.