In this work, the HP model and Monte Carlo Method are used to study the effect hydrophobic on the folding problem. We used a lattice model and several chains with distinct proportions of hydrophobic residues. We investigate how the hydrophobic residues number of the chains can influence its folding. For each simulation, we measure three parameters: Energy, End-to-End Distance and Radius of Gyration. The geometry of the final chains was analyzed too. The simulations show that the proportion of hydrophobic residues in the chain is very important for the folding. New simulations have been showed that the position of theses residues is important to the chain.