Model for quantitative analysis of the concentration of phosphorus removed (relative to the final pH of the leaching solution) during leaching of iron oxide ore in oxalic acid solution has been derived. It was observed that the validity of the model is rooted in the expression lnP = (γ +Nlnγ) where P is the concentration of phosphorus removed during the leaching process, N is 0.57;dissolution coefficient of phosphorus in oxalic acid solution, and γ is the final pH of the leaching solution at the time t, when the concentration of phosphorus is evaluated, and both sides of the expression are correspondingly approximately equal. The model; P = e ^{(γ + 0.57 lnγ)}depends on the value of the final pH of the leaching solution which varies with leaching time. The maximum deviation of the model-predicted concentration of removed phosphorus from the corresponding concentration obtained from the experiment was less than 22%. The concentrations of phosphorus removed per unit mass of iron oxide ore added as obtained from experiment and derived model are 3.8329 and 4.0614 mg/kg/g respectively which are in proximate agreement.