  In this paper, we establish a structure theorem for a smooth projective
variety $X$ with semi-positive holomorphic sectional curvature. Our structure
theorem contains the solution for Yau's conjecture and it can be regarded as a
natural generalization of the structure theorem proved by Howard-Smyth-Wu and
Mok for holomorphic bisectional curvature. Specifically, we prove that $X$
admits a locally trivial morphism $\phi:X \to Y$ such that the fiber $F$ is
rationally connected and the image $Y$ has a finite \'etale cover $A \to Y$ by
an abelian variety $A$, by combining the author's previous work with the theory
of holomorphic foliations. Moreover, we show that the universal cover of $X$ is
biholomorphic and isometric to the product $\mathbb{C}^m \times F$ of the
universal cover $\mathbb{C}^m$ of $Y$ with a flat metric and the rationally
connected fiber $F$ with a K\"ahler metric whose holomorphic sectional
curvature is semi-positive.
