  In this paper, we propose a new class of parametrization of the equation of
state of dark energy. In contrast with the famous CPL parametrization, these
new parametrization of the equation of state does not divergent during the
evolution of the Universe even in the future. Also, we perform a observational
constraint on two simplest dark energy models belonging to this new class of
parametrization, by using the Markov Chain Monte Carlo (MCMC) method and the
combined latest observational data from the type Ia supernova compilations
including Union2(557), cosmic microwave background, and baryon acoustic
oscillation.
