A high-temperature superconducting (HTS) radio-frequency (rf) coil has been proposed as a promising tool in the investigation of tissue microscopy with high resolution due to its low-resistant characteristic for magnetic resonance (MR) probe design. In this work, a 200 mm in diameter Bi2Sr2Ca2Cu3Ox (Bi-2223) tape HTS rf coil was built; and a signal-to-noise ratio (SNR) with the HTS tape coil having 2.22 folds higher than that of a home-made copper coil for a phantom MR study was demonstrated. Testing results were in agreement with predicted ones, and the difference between the predicted SNR gains and measured SNR gains is 0.9%. Using in vivo imaging, a SNR with the HTS tape coil having 1.95 folds higher than that of a home-made copper coil for a human hand MR study was presented. The HTS coil is expected to generate a higher SNR gain after optimization. Further applications of a functional magnetic resonance imaging system are under investigation to test the applicability of this HTS coil system in a 3T system.