It is a longstanding problem that whether there exists a complex structure on the 6-dimensional sphere? Many famous mathematicians have made efforts on this problem, such as Hopf, Wen-tsun Wu, Borel, Serre, LeBrun, Shiing-Shen Chern, Atiyah, etc. Taking advantage of isoparametric theory, we construct complex structures on certain isoparametric hypersurfaces and focal submanifolds in the unit sphere. As a consequence, there is a closed 8-dimensional manifold N^8 such that there exists a complex structure on S^6X N^8. This talk is based on joint works with Professor Zizhou Tang and Professor Chao Qian.