  We consider the Friedberg-Lee symmetry for the quark sector and show that the
symmetry closely relates to both quark masses and mixing angles. We also extend
our scheme to the fourth generation quark model and find the relation
$|V_{tb^{'}}| \simeq |V_{t^{'}b}| \simeq m_b/m_{b^{'}}< \lambda^2$ with
$\lambda\simeq0.22$ for $m_b=4.2\ \gev$ and $m_{b^{'}}>199\ \gev$.
