Photodynamic therapy (PDT) was started in the People's Republic of China in the early 1980s after domestically produced hematoporphyrin derivative (HpD) became available. Since then, numerous photosensitizers have been synthesized and evaluated. Several promising ones have undergone clinical investigations and a few have entered into formal clinical trials. Various lasers and non-coherent light sources have been developed in China to facilitate domestic photosensitizers and clinical PDT applications. Chinese pioneered PDT protocols for treating nasopharyngeal carcinoma, liver carcinoma, port-wine stains (PWS) and urethral condylomata acuminata. Over the past 25 years Chinese physicians have treated several thousands patients, gained substantial experience in both basic sciences and clinical applications, and generated a great number of clinical reports. PDT related research and clinical activities would most likely continue to grow in China. The Part One of this article provides an overview on China's PDT history and domestic photosensitizers. Clinical PDT data of nasopharyngeal carcinoma, liver cancer and port-wine stains will be discussed in the Part Two of this article.