Recently oil field development of Formosa became very active in all over the island, worked by the most up-to-date method, and some promising fields has been discovered. In this paper I have described the short historical and geological sketches of oil fields of the island as well as the present situation of two producing fields and several prospecting districts there. Lastly I put my opinion on the so-called 3, 000 m deep oil well, drilling in some districts.