The aim of the study was to investigate lead levels in soil and plant samples collected near a highway in an agricultural area in Oman. It was found that contamination by lead decreased rapidly with increasing distance from the highway in both soil and plant samples. Atmospheric depositions appeared to be the main contributor to the plant contamination by lead. Lead content was determined for the unwashed and washed leaflets of the date palm trees collected from the study area. Differences in the lead levels between the washed and unwashed samples indicated that a large portion of the metal exist as superficial contaminants that could be removed by washing. Moreover, a number of tomato plants were grown under the shade house in soils containing lead concentrations of 5, 10, 50, 100, 500, and 1000 ppm in order to study the effect of soil pollution on plants. The amount of lead uptake by the plants was found to be positively correlated with the amount of lead in the soil. Whereas, the percentage of the uptake showed negative correlation with lead concentration in the soil. Roots of plants grown in the soil concentrations of 100, 500; and=1000 ppm were found to be considerably shorter and brownish-in color in contrast-with-the: control plants of the same agaxPrótein analysis by gel electrophoresis revealed the presence of two new proteins in the treated plants. Estimation of the molecular weight showed that they are low molecular-weight-proteinş.