OBJECTIVE: To establish the method for simultaneous determination of 6 components in Lonicera japonica, and to study the content changes of them before and after before and after carbonized. METHODS: UPLC method was adopted. The determination was performed on Agilent Eclipse Plus C18 RRHD column with mobile phase consisting of 0.1% phosphoric acid solution-acetonitrile (gradient elution) at the flow rate of 0.2 mL /min. The detection wavelength was set at 350 nm, and column temperature was 25 ℃. The sample size was 1 μL. RESULTS: The linear ranges of chlorogenic acid, rutin, galuteolin, isochlorogenic acid A, isochlorogenic acid B and isochlorogenic acid C were 21.2-424 μg(r=0.999 3), 1.17-23 μg(r=0.999 5), 2.18-43 μg(r=0.999 8), 5.10-102 μg(r=0.999 3), 2.60-52 μg(r=0.999 1), 4.95-99 μg(r=0.999 8), respectively. RSDs of precision, stability and repeatability tests were all lower than 2.0%. Recoveries were 97.11%-99.76%(RSD=1.20%,n=6), 95.20%-99.90%(RSD=2.20%,n=6), 95.71%-100.30%(RSD=2.20%,n=6), 95.00%-96.98%(RSD=0.88%,n=6), 96.47%-103.00%(RSD=2.40%,n=6), 95.78%-103.80%(RSD=3.20%,n=6). Compared with before processing, the contents of rutin, isochlorogenic acid B and isochlorogenic acid C in L. japonica were increased along with processing, the contents of chlorogenic acid and isochlorogenic acid A were decreased significantly, while the content of galuteolin had no significant change. CONCLUSIONS: The method is simple, precise, stable and repeatable, and can be used for simultaneous determination of 6 components in L. japonica. Those chemical components have certain changes before and after carbonized.