In order to research into the cytology mechanism of anti-virus action of total flavone of    Scutellaria barbata (TFSB), the effects of TFSB on host cells membrane potential, Na⁺-K⁺-ATPase activity and membrane fluidity after parainfluenza virus type1 (PIV-1) infection were studied.  The changes of membrane potential which was fluorescent labeled with DiBAC₄(3) and its changes were measured by flow cytometer.  Phosphorus determination method and spectrophotometry were used to measure the Na⁺-K⁺-ATPase activity of Hep-2 cells membrane after PIV-1 infection.  Hep-2 cells membrane phospholipids were fluorescent labeled with NBD-C6-HPC and membrane fluidity was measured by confocal scanning laser microscope.  The result demonstrated that post PIV-1 infection membrane potential decreased significantly and the membrane was in a state of hyperpolarization, Na⁺-K⁺-ATPase activity increased significantly and membrane fluidity decreased  significantly.  There was no apparent interfere effect of TFSB on the changes of membrane potential and Na⁺-K⁺-ATPase activity after PIV-1 infection, while membrane fluidity improved significantly.  It was indicated that the cytology mechanism of PIV-1 infection might be related to membrane hyperpolarization, Na⁺-K⁺-ATPase activity increase and membrane fluidity decrease.  TFSB can improve membrane fluidity and prevent the    infection by protecting the cell membrane.  But it is possible that the anti-PIV-1 mechanisms of TFSB had nothing to do with membrane potential and Na⁺-K⁺-ATPase activity.