In this project, we study the initial state radiation (ISR) process $e^{+}e^{-}\to\pi^{+}\pi^{-}\pi^{0}(\gamma)$ at center-of-mass (c.m.) energy $\sqrt{s}=1019$ MeV corresponding to the $\phi$-meson mass. An integrated luminosity $\sim1.62~\text{fb}^{-1}$ data sample collected during period 2004-2005 at KLOE is used in this analysis. The ISR technique is applied for the first time to provide the data set below 1 GeV. Studying the measured $3\pi$ invariant mass spectrum, the analysis aims to obtain the total cross section of the process $e^{+}e^{-}\to\pi^{+}\pi^{-}\pi^{0}$ in the energy range $[720, 820]~\text{MeV}$. Further goals of this study is to extract the peak cross section of the process $e^{+}e^{-}\to{V}\to3\pi$, involving vector resonances $V=\omega,\phi$ and to measure cross section of non-resonant process $e^{+}e^{-}\to\gamma^{*}\to3\pi$. Products of branching fractions $\mathcal{B}(\omega\to{e}^{+}e^{-})\mathcal{B}(\omega\to3\pi)$ will also be determined.