Song feels that there is no reason why the club can't follow in the example of Atletico Madrid, in La Liga, in making a surge for the Champions League places.
He told The Mirror: "The future of the club is very good. That's why I chose to come here. In Spain nobody was expecting anything from Atletico Madrid and look at how well they are doing.
"You have to look at examples like that. The way that West Ham are looking now, in the next five years they will be one of the best clubs in England.
"When I see the way that we play and where we are at the moment I know that I made a very good choice."
West Ham face Stoke City in their next Premier League outing on Saturday.