  We study the relation between CKLS model and CIR model. We prove that under a
suitable transformation, any CKLS model of order $\frac{1}{2}<\gamma<1$ or
$\gamma> 1$ corresponds to a CIR model under a new probability space. Moreover,
we get the explicit solution and the precise distribution of the CKLS model at
any time $t$ under the new probability measure. We also give the moment
estimation of CKLS model.
