Pion Structure Function $F_{2}^{\pi}$ in the Valon Model

Partonic structure of constituent quark (or{\it{valon}}) in the Next-to-Leading Order is used to calculate pion structure function. This is a further demonstration of the finding that the constituent quark structure is universal, and once it is calculated, the Structure of any hadron can be predicted thereafter, using a convolution method, without introducing any new free parameter. The results are compared with the pion structure function from ZEUS Coll. Leading Neutron Production in $e^{+}p$ collisions at HERA. We found good agreement with the experiment. A resolution for the issue of normalization of the experimental data is suggested. In addition, the proportionality of $F_{2}^{\pi}$ and $F_{2}^{p}$, which have caused confusion in the normalization of ZEUS data is discussed and resolved.