Nitrogen doped carbons are an important family of materials with ideal activity for oxygen reduction reaction(ORR). It is always interesting to search functional carbons with high heteroatom contents and desirable structure for ORR. Within this study, the surface modification of carbon nanotubes(CNTs) via hydrothermal carbonization(HTC) technique in the presence of glucose and urea was reported, where the surface of CNTs is successfully coated by nitrogen containing hydrothermal carbon layers. The resulting composite combines both advantages of the outstanding electrical conductivity of CNTs and the effective ORR active sites provided by doped nitrogen in the HTC carbon layers. By controlling the ratio of glucose and urea, the nitrogen contents coated on the surface of CNTs can reach up to 1.7 wt%. The resulting materials show outstanding electrochemical activity towards ORR in alkaline electrolyte, making it one of the valuable metal-free electrode materials and a competent alternative to the state-of-the-art Pt/C catalyst. Nitrogen doped carbons are an important family of materials with ideal activity for oxygen reduction reaction (ORR). It is always interesting to search for functional carbons with high heteroatom contents and desirable structures for ORR. Within this study, the surface modification of carbon nanotubes ) via hydrothermal carbonization (HTC) technique in the presence of glucose and urea was reported, where the surface of CNTs is successfully coated by nitrogen containing hydrothermal carbon layers. The resulting composite combines both advantages of CNTs and the effective ORR active sites provided by doped nitrogen in the HTC carbon layers. By controlling the ratio of glucose and urea, the nitrogen contents coated on the surface of CNTs can reach up to 1.7 wt%. The resulting materials show outstanding electrochemical activity towards ORR in alkaline electrolyte , making it one of the valuable metal-free electrode materials and a competent alternativ e to the state-of-the-art Pt / C catalyst.