The main objective of the study is to explore the knowledge level of farmers in Riyadh region regarding the negative effects of intensive use of chemical fertilizers on soil pollution .The total sample size amounted to 200 respondent farmers . The main results showed that 51%of the respondents had high knowledge level for the negative impact of the intensive use of the chemical fertilizers .While the percentage of respondents of high knowledge level for the means of pollution restriction was 72.5% . Also significant positive correlations were found between the degree of respondents knowledge for the negative inputs of the intensive use of the-chemical fertilizers as a dependent variable and each of their : degree of education , annual income , degree of contact with sources of information and the number of the agricultural activities :On the other hand there was. a negative correlation between each of :.the age and the number of non family members of agricultural workers