||Carbon nanotube(CNT) possesses the strong potential to be utilized in various applications due to its extraordinary mechanical, electrical and thermal properties. However, in reality, it has not been applied in various industries because of its practical limits arising from its short length and poor solubility. Of various methods to assemble individual CNTs into a long CNT fiber, wet spinning method using the advantages of CNT liquid crystals formed in chlorosulfuric acid(CSA) can produce a strong and multi-functional CNT fiber with high alignment and density. In the study, we demonstrate that small amount of oxygen incorporated into CNTs during the purification process greatly increases their solubility in CSA and established the optimal purification process to significantly increase the solubility of CNTs in CSA. Also the wet spinning from the CNT liquid crystal dope with high concentration of CNTs in CSA was performed.