[en] In order to better understand the nature of active region outflows, the electron density was measured by using a density-sensitive line pair, Fe xiv 264.78 Å/274.20 Å. Because coronal line profiles of the outflow region are composed of a major component with a Doppler shift of $⩽<!--\; ???\; -->10\mathrm{k}\mathrm{m}{\mathrm{s}}^{-<!--\; ???\; -->1}$ and a minor component (enhanced blue wing, EBW) blueshifted by up to $100\mathrm{k}\mathrm{m}{\mathrm{s}}^{-<!--\; ???\; -->1}$, we extracted EBW from the line profiles through double-Gaussian fitting. We tried applying the simultaneous fitting to those two Fe xiv lines with several physical restrictions. Electron density for both components ($n_{\mathrm{M}\mathrm{a}\mathrm{j}\mathrm{o}\mathrm{r}}$ and $n_{\mathrm{E}\mathrm{B}\mathrm{W}}$, respectively) was calculated by referring to the theoretical intensity ratio as a function of electron density as per the CHIANTI database. We studied six locations in the outflow regions around NOAA AR10978. The average electron density was $n_{\mathrm{M}\mathrm{a}\mathrm{j}\mathrm{o}\mathrm{r}}={10}^{9.16\pm <!--\; ??\; -->0.16}\mathrm{c}{\mathrm{m}}^{-<!--\; ???\; -->3}$ and $n_{\mathrm{E}\mathrm{B}\mathrm{W}}={10}^{8.74\pm <!--\; ??\; -->0.29}\mathrm{c}{\mathrm{m}}^{-<!--\; ???\; -->3}$. The magnitude relationship between $n_{\mathrm{M}\mathrm{a}\mathrm{j}\mathrm{o}\mathrm{r}}$ and $n_{\mathrm{E}\mathrm{B}\mathrm{W}}$ was the opposite in the eastern and western outflow regions. The column depth was also calculated for each component, which leads to the result that the outflows possess only a small fraction (∼0.1) in the eastern region, whereas they dominate over the major component in the line profiles by a factor of five in the western region. When taking into account the extended coronal structures, the western region can be thought to represent the mass leakage. In contrast, we suggest a possibility that the eastern region actually contributes to mass supply to coronal loops.