A gel pad for facilitating ultrasound scanning between an ultrasound transducer and a skin surface is provided. The gel pad has a first surface being bendable with a small degree and maintained locally flat, and a second surface being more bendable than the first surface for contacting the skin surface. A coupling media is arranged between the first and second surface with a stiffness gradient increasing from the second surface to the first surface. The first surface is capable of facilitating the ultrasound transducer to move swiftly on the gel pad. The second surface is capable of conforming to a non-uniform shape of the skin surface. On the first or second surface, position markers are provided for determining coordinates of the ultrasound transducer, by blocking ultrasound signals from transmitting through the gel pad to generate dark strips or marks in the ultrasound images.