  A systematic method developed by the authors to evaluate the one-loop
electromagnetic self-energies of the low-lying mesons is extended to the
calculation of the vector sector including $\rho$, $\omega$, and $\phi$-mesons.
The theoretical result of $\rho^0-\rho^\pm$ electromagnetic mass difference is
in agreement with the measurements. An interesting effect called as
electromagnetic mass anomaly of the massive Yang-Mills particles is further
discussed. There is no new parameter in this study.
