Photoacoustic Tomography (PAT) is a promising medical imaging modality by reason of its particularity. It combines optical imaging contrast with the spatial resolution of ultrasound imaging, and can distinguish changes in biological features in an image. For these reasons, many studies are in progress to apply this technique for diagnosis. But, real-time PAT systems are necessary to confirm biological reactions induced by external stimulation immediately. Thus, we have developed a real-time PAT system using a linear array transducer and a custom-developed data acquisition board (DAQ). To evaluate the feasibility and performance of our proposed system, two types of phantom tests were also performed. As a result of those experiments, the proposed system shows satisfactory performance and its usefulness has been confirmed.