The electrical conductivity and electro-thermal temperature rise of carbon fiber reinforced cement mortar under dry and wet conditions were studied separately.Results show that when carbon fiber content is 0.3% mass fraction,electrical conduction depends on the hydrated ion mainly.Electrical conductivity and electro-thermal temperature rise under wet condition are superior to those under dry condition.Increasing the fiber content from 0.3% mass fraction to(0.7)% mass fraction reduces the space between carbon fiber gradually,so that tunnelling effect of carbon fiber becomes more dominant than hydrated ion in governing the electrical conduction.As a result of two kinds of electric conduction mechanisms synergism,electrical conductivity under wet condition are still superior to those under dry condition,but electro-thermal temperature rise under wet condition are inferior to those under dry condition.When carbon fiber content is(1.0%) mass fraction,the conductive network is formed by fibers physical contact,electrical conduction mainly depends on the conductive network and the hydrated ion electric conduction is negligible.In this case,electrical conductivity and electro-thermal temperature rise under wet condition are inferior to those under dry condition.