An electrochemical sensor based on PEDOT: PSS-beta-CD-SWCNT-COOH/GCE for highly sensitive analysis of shikonin (SHI) in PBS buffer solution was reported. PEDOT: PSS-beta-CD-SWCNT-COOH composite was obtained by using poly(3,4-ethylenedioxythiophene): poly(4-styrenesulfonate) (PEDOT: PSS), beta-Cyclodextrin (beta-CD) and carboxylated single-walled carbon nanotube (SWCNT-COOH) to modify glassy carbon electrode (GCE) and characterized by scanning electron microscopy and electrochemical impedance spectroscopies. In optimized conditions, PEDOT: PSS-beta-CD-SWCNT-COOH had a high sensitivity to SHI and it could detect SHI in linear ranges 6 nM to 30 mu M with a low detection limit of 1.8 nM. And a series of experiments showed that the modified electrode exhibited good repeatability, reproducibility, and selectivity to electrochemical determination of SHI. (c) 2019 The Electrochemical Society.