Hadron Structures and Perturbative QCD

In the first part of this talk, I will summarize recent developments in the study of the chiral-odd spin-dependent parton distributions h_1(x,Q^2) and h_L(x,Q^2) of the nucleon, in particular, (i) Next-to- leading order Q^2 evolution of h_1(x,Q^2) and (ii) Leading order Q^2 evolution of the twist-3 distribution $h_L(x,Q^2)$ and the universal simplification of the Q^2 evolution of all the twist-3 distributions in the large $N_c$ limit. The second part of this talk will be devoted to a systematic analysis on the light-cone distribution amplitudes of vector mesons ($\rho$, $\omega$, $\phi$, $K^*$ etc) relevant for exclusive processes producing these mesons. In particular, twist-3 distribution amplitudes are discussed in detail.