  We study the parameter estimation problem of Vasicek Model driven by
sub-fractional Brownian processes from discrete observations, and let
{S_t^H,t>=0} denote a sub-fractional Brownian motion whose Hurst parameter
1/2<H<1 . The studies are as follows: firstly, two unknown parameters in the
model are estimated by the least squares method. Secondly, the strong
consistency and the asymptotic distribution of the estimators are studied
respectively. Finally, our estimators are validated by numerical simulation.
