Before revision:  The ] basic risky asset price model  we construct here is  drift uncertain and volatility uncertain , we describe such model by using general G-Brownian motion and call it as G-asset price system.
After revision:  The ], to construct the model of the risky asset price and bid-ask pricing for the European contingent claims under Knightian uncertain financial market. Firstly, we consider the basic risky asset price model we construct here is drift uncertain and volatility uncertain , we describe such model by using general G-Brownian motion and call it as G-asset price system.