The present invention provides a light transmittable and tissue integration integrable biofiber device including a plurality of biofibers. The plurality of biofibers consist a single bare fiber or a single constructed fiber. The single constructed fiber consists a core layer and either a single cladding layer or a plurality of cladding layers, and the cladding layer clads and fuses a circumferential surface of the core layer. Each of the plurality of biofibers comprises a light receiving end and a light emitting end, a light radiates through the light receiving end and the light is emitted from the a light emitting end. Therefore, the biofiber device of the present invention may simultaneously accomplish light transmittable and tissue integrable purposes to facilitate light therapy, optical gene therapy and optogenetics.