During January $2002{sim}April;2004$, hydrogen peroxide ($H_{2}O_{2}$) measurements were performed at the campus of Korea University, which is located in the northeastern part of Seoul. Gas phase hydroperoxide was collected in aqueous solution and separated by HPLC. Concentrations were determined by fluorescence using postcolumn enzyme derivatization. This measurement system was improved to be run automatically from sample collection at every 10 minutes through chemical analysis for data collection. Detection limits of $H_{2}O_{2}$ is $10{sim}17;pptv$, and the overall uncertainty of the measurements is better than 8%. Two-year measurements of $H_{2}O_{2}$ show typical seasonal variations. Concentrations of $H_{2}O_{2}$ were higher during $June{sim}October$ and lower during $January{sim}February$. Maximum concentration of 1-hour averaged $H_{2}O_{2}$ was 6.5 ppbv, which was observed in August and September. In general $H_{2}O_{2}$ concentrations were well correlated with $O_{3}$ concentrations and largely affected by meteorological factors such as temperature and wind direction.