In this paper, the situation of intestinal parasites infection among primary school students was investigated. This study was carried out with sample size of 394 student from 30 selected primary school in Arak city. Selection of chasses and students made by stratified method and stool examination done with direct and indirect method. The research methodology was based on analysis of data obtained from, 3 times stool examination of all students in the sample group. The results of the research from that : 63.5% of students were infected by parasites (pathogene and nonpathogene), In among pathogenic parasites , giardia with 27.7% and h.nana with 6.35 had the highest prevalence. Prevalence of the other intestinal parasites were: Ascaris 1.5%, Oxyuris 1.5% ( nonepecific method ), Entamoeba histolytica 2.5%, Entamoeba coli 29.4%, Entamoeba Hartman 2.2%, Endolimax 12.4%, Iodamoeba 3.5%, Blastocystis 2.2% , Chlomastix 2%. The results also showed that there is no significant relation between infection date and demographic factors such as: age, sex, parents job and , geographic area.
