X-ray diffraction patterns of $epsilon$-FeSi has been measured at pressures up to $sim$53 GPa with good signal-to-noise ratio and high resolution using synchrotron radiation. Rietveld analysis has been performed. indent The structure of $epsilon$-FeSi is a cubic with space group P$2_{1}$3, a=$4.4781 pm 0.0026 AA$.A third order Birch-Murnaghan equation of state fit to the experimental data yields $V_{0}=89.80 pm 0.15 AA^{3}$, with a $B_{0}$ of $204.7 pm 4.9$ GPa and $B_{0}^{'}=5.6 pm 0.3$. The bulk modulus obtained from this study is not only in very good agreement with those of some previous experimental studies but also in good agreement with those obtained by first-principle calculations.