Aim: To record the single-channel currents and characterize the electrophysiological properties of the Cl~- channels inhuman sperm membrane. Methods: The membrane proteins extracted from the human sperm were reassembled intoliposome bilayer, and the liposomes were fused into giant liposomes with a diameter more than 10μm by dehydration-rehydration procedure. The giant liposomes were used to study the Cl~- channel activities by patch-clamp technique.Results: By patch clamping the giant liposome in an asymmetric NMDG (N-methyl-D-glucamine)-Cl (bath 100//pipette 200 mmol/L) solution system, three kinds of single-channel events with unit conductances of (74.1 ± 8.3) pS,(117.0±5.7) pS and (144.7±4.5) pS, respectively, were detected. Their activities were voltage-dependent and allwere blocked by SITS (4-acetamido-4’-isothiocyanato-stilbene-2’, 2’-disulfonic acid) in a concentration-dependentmanner. By constructing the open and close dwell time distribution histograms and then fitting them with exponential Methods: The membrane proteins extracted from the human sperm were reassembled intoliposome bilayer, and the liposomes were fused into giant liposomes with a diameter The more than 10 μm by dehydration-rehydration procedure. The giant liposomes were used to study the Cl ~ - channel activities by patch-clamp technique. Results: By patch clamping the giant liposome in an asymmetric NMDG (N-methyl-D-glucamine) Cl (bath 100 // pipette 200 mmol / L) solution system, three kinds of single-channel events with unit conductances of (74.1 ± 8.3) pS, (117.0 ± 5.7) pS and (144.7 ± 4.5) pS, respectively, were detected. Their activities were voltage-dependent and allwere blocked by SITS (4-acetamido-4’-isothiocyanato-stilbene-2 ​​’, 2’-disulfonic acid) in a concentration-dependentmanner. and then fitting the m with exponential