Disclosed is an ultrafine fiber including lignin, a carrier polymer and a carbon material. The ultrafine fiber, which includes lignin, can exhibit the properties of lignin such as antibacterial property, biodegradability, etc. Accordingly, it can be used widely in medical materials such as nanofiber, nanofiber web, nanofiber sheet, etc. for wound healing of the skin's dermal layer. Also, the ultrafine fiber can be used in sheath of electric cables because it contains a carbon material and has superior conductivity. In addition, because the ultrafine fiber can hold a large quantity of water, it can be used in various fields including sanitary pads for women, diapers for babies and adults, etc.