Carbon nanohorn (CNH) doping in MgB 2 wire prepared by suspension spinning was studied to enhance flux pinning. The mixed powders of MgB 2 and CNH with nominal composition of (MgB 2 ) 0.95 C 0.05 were suspended in a mixed poly(vinyl alcohol) solution. The as-drawn filaments were hot-pressed under 20MPa at 200°C for 8h. The samples were enveloped by an iron sheet with a pellet of mixed powder of Mg and B and vacuum-sealed in a fused quartz tube, and then sintered at the temperature ranging from 885°C to 900°C for 2–3h. The superconductivity of the samples was studied by electrical resistivity and SQUID method. Serious deterioration of T c was not observed for the doped sample. The CNH doping resulted in enhancement of the transport J c values at 4.2K in high fields ranging from 6T to 10T by sintering at 885°C for 2h. The superconductivity at 4.2K was maintained by applying the field of 14T for the doped sample sintered at 900°C for 3h.