Natural gas in the form of compressed natural gas (CNG) has a pressure of 20 MPa. Glass fiber/vinyl ester composite has potential to be formed into a CNG tube. This study uses a numerical analysis method and tubular approching to assess composite ability to accept internal pressure loading, refered to failure criteria Tsai-Hill. The number of layers and fiber direction are chosen as independent variable. Configuration angle (+70, +25) provided a more optimal result than using a single angle. Composites are in a safe condition on 180th layer. Thus, the glass fiber composite material / vinyl ester is not recommended to apply in the CNG tube manufacture.