The　aim　of　this　work　was　to　study　the　effects　of　tetramethylpyrazine　(TMP)　on　the　interaction　between　lymphocyte　function-associated　antigen-1　(LFA-1)　and　intercellular　adhesive　molecule-1　(ICAM-1)　by　micropipette　technique.　A　pair　of　cells,　i.e.,　a　human　lymphocyte　or　a　SKW-3　cell　(human　T　cell　leukemia),　LFA-1　was　expressed　on　which　cellular　surfaces,　and　a　RBC　coupled　with　ICAM-1,　were　the　carriers　for　LFA-1　and　ICAM-1.　The　adhesion　probabilities　of　this　pair　of　cells　were　mediated　by　specific　interactions　between　ICAM-1　and　LFA-1.　Phytohemagglutinin　(PHA)　stimulation　resulted　in　the　significant　increase　in　the　adhesion　probability　compared　to　the　resting　lymphocyte.　TMP　treatment　can　inhibit　such　increase　and　even　make　the　adhesion　probability　lower　than　the　resting　state.　While　the　LFA-1　expression　has　not　changed　significantly　with　PHA　stimulation　or　with　TMP　treatment,　which　indicated　that　TMP　inhibiting　effects　was　realized　by　a　possible　conformation　change.