Purpose: the main aim of this research was to determine the effect of bibliotherapy on the reduction of depression among 7 to 12 years old children in Tehran’s social welfare organization.
Methodology: This applied research implemented by semi-empirical method and the sample of the research were 15 girls aging form 7 to 12 in “Dar-Al-Qora Orphanage Center”, Located in Tehran, Iran. For implementation of the research, we used pre-test, past-test technique. Maria Cowax depression test was carried out befor application of interference. bibliotherapic interference was applied to childes as pre-test by offering selected, suitable books to childes, introduced by Institute for Intellectual Development of Children and Young Adults (IIDCYA), along with group instruction and book reading sessions. After application of interference in 2 month, Maria Cowax test carried out again.
Findings: Using Mann Whitney U test analyze on the data in pre-test/post-test, gathered from Maria Cowax depression test, showed that there was a significant difference between the childes of test group and evidence group and degree of depression in test group significantly decreased, on the basis of Maria Cowax depression test data. We can conclude that the treatment had a positive effect on  the childes and reduced their depression degree.
Originality/ Value: Originality of this research consists of the scientific confirmation of the effect of bibliotherapy on the reduction of depression. Managers of orphanage centers or other rehabilitation centers can use IIDCYA suitable books for bibliotherapic purposes and reduction of depression.