Fibrous carbon nanohorn aggregates and method for producing same

The invention, the purpose of which is to provide carbon nanohorn aggregates having an excellent conductivity-imparting property and carbon nanohorn aggregates having both an excellent conductivity-imparting property and dispersibility, provides fibrous carbon nanohorn aggregates aggregating a plurality of single-walled carbon nanohorns; these fibrous carbon nanohorn aggregates have an excellent conductivity-imparting property, can be produced by the same process as spherical carbon nanohorn aggregates, and mixed fibrous and spherical carbon nanohorn aggregates have both high conductivity and high dispersibility.