Abstract: β-cyclodextrin ( BC) was used to improve the antioxidantand microstructure stability of fermented barley extract with Lactobacillus plantarum ( LFBE) in order to keep bioactivity of LFBE. LFBE was embedded with BC ( BLFBE) and dried with freed-dried method.X-ray diffraction and scanning electron microscope technologies were used to analyze microstructure of BLFBE.The results of antioxidant experiments showed that polyphenol content in LFBE decreased from ( 0.30 ± 0.11) mg/m L to ( 0.019 ± 0.0023) mg/m L, its DPPH clearance reduced from 67.95% ± 2.16% to 9.16% ± 0.65%, and its ·OH clearance decreased from 72.97% ± 3.01% to 11.14% ± 3.16% after storing 12 h at normal temperature. After LFBE embedded with1.6 mg/m L BC, polyphenol content of BLFBE merely decreased from ( 0.25 ± 0.015) mg/m L to ( 0.21 ± 0.01) mg/m L, its DPPH clearance only reduced from 52% ± 2.01% to 45% ± 2.43%, and its ·OH clearance only decreased from 67.16% ± 1.31% to54.74% ± 2.53%.The results of chroma experiments indicated that BC inhibited the browning of LFBE.The results of scanning electron microscope showed that LFBE was irregular sheet structure, but appeared near-spherical structure after embedded with BC.X-ray diffraction experiment indicated that LFBE powder was armorphous and shapeless structure, but BLFBE appeared crystal structure after embedded with BC.Therefore, BC significantly inhibited the descent on antioxidant activity of LFBE, and embedding function of BC also improved structural stability of BLFBE.