The potassium channel Kv 1.3 plays a vital part in the activation of T lymphocytes and is an attractive pharmacological target for autoimmune diseases.BmP02,a peptide with 28 residues from the venom of Chinese scorpion Buthus martensi Karsch,is considered as a potent and selective Kv1.3 channel blocker.However,the mechanismofits recognition on target-channelis still unclear.In the present study,a complex molecular model of Kv1.3-BmP02 was establishedbydocking analysis and molecular dynamics simulations,in which alarge β-turn of BmP02was probably acting as the binding interface.On the one hand,the functional motif composed by His9,Lys11 and Lys13 was identifiedas the key sitesforBmP02recognizingKv1.3throughalanine-scanning.On the other hand,negatively charged residues of Kv1.3,D421 and D422,located in turret region was proved to determinethe sensitivityto BmP02 by site-directed mutagenesis and patch clamping,which suggested that the electrostatic attraction force played crucial roles in the initial Kv1.3-BmP02 interaction.This study revealedthe molecular basis of BmP02 recognizingKv1.3 and provided a novel interactionmodel for Kvchannel-specific blocker complex,which may help to set strategy in the drug-designing for Kv1.3-related channelopathies.