We examined the dependence of the growth of undoped InP epilayer by chloride vapor phase epitaxy on the growth temperature and on the $PCl_3$molar fraction. The growth temperature was varied from $620^{circ}C$ to $650^{circ}C$ and the $PCl_3$molar franction from $2.5{ imes}10^{-2}$ to $4.5{ imes}10^{-2}$. The undoped InP epilayer with hillock free surface was obtained at the growth temperature of $640^{circ}C$ and at the PCl$_3$molar fraction of $3.0{ imes}10^{-2}$. The surface morphology was improved with a decrease of the PCl$_3$molar fraction. The carrier concentration measured by Hall and ECV was less than $1{ imes}10^{14}cm^{-3}$. The resistivity of the undoped InP epilayer, measured by using four probe method, showed a high value of <$3.0{ imes}10^6{Omega} extrm{cm}$.