Extensive Monte Carlo folding simulations for four proteins of various structural classes are carried out, using a single coarse-grained potential which is off-lattice and continuous . Our work is a bridge between works based on all-atom potental, which is computationally expensive and consequently difficult to observe folding, and overly simplified models such as lattice or Go-type models. Also, to the best of or knowldege, it is for the first time that the folding simulations for various proteins are succesfully performed for proteins of various structural classes using a single potential.