  The electromagnetic (EM) form fators of the pseudoscalar and vector mesons
are calculated in the light-front framework. We extract these form factors from
the relevant matrix elements directly, instead of choosing the Breit frame. The
results show that the charge radius of the meson are related to both the first
and second longitudinal momentum square derivative of the momentum distribution
function. In addition, the static properties of the EM form factors and the
heavy quark symmetry of the charge radii are checked analytically when we take
the heavy quark limit.
