The move came as little surprise since the owner had warned about possible cancellations in February, due to delays.
The initial order was for four 75,750-dwt ice-class panamax bulkers.
DryShips had paid $11.5m for the vessels but it got that money back plus interest.
It still had to pay $124.4m before the decision to cancel the deal.
As TradeWinds reported last week, Rongsheng, which has been unable to secure any orders during the past two years, could be taken over by Shanghai Waigaoqiao Shipbuilding.
