The study was carried out to develope quantitative analysis method of individual sugars in licorice extract. Individual sugars were analyzed by HPLC equipped with Refractive Index(RI) Detector. R values of sucrose and glucose were 1.0000 and R values of fructose and maltose were 0.9999. Standard calibration curve showed good linearity. Detection limit of sugars was in the range of 1.58 to 3.92 ${mu}g$. Recovery rate of fructose, glucose, sucrose and maltose was $99.4~102.2\%,;92.3~97.9\%,;99.4~102.0\%,;91.1~101.0$ respectively. Measure uncertainty was calculated to confirm trust and accuracy of analytical results. Main uncertainty factors were standard purity and HPLC replication injection. In $95\%$ trust level expanded uncertainty of sugars in licorice extract were fructose $1.98pm0.047,;glucose;1.32pm0.065,;sucrose;11.69pm1.177,;maltose;1.06pm0.042;g/100;g$.