Background: The healing power of the sun and its use in medical treatment (heliotherapy) hasrnextended back into ancient times. However, sunlight exposure of skin is the vital part for thernproduction vitamin D in human being, vitamin D deficiency is common problem even in countryrnwith abundant sun shine throughout the year and this problem is worsening on infant. In differentrncountries of the world the prevalence of vitamin D deficiency in infant is believed to be rangern2.7% to 45%. This is may be due to inappropriate practice of sunlight exposure. Therefore thernpurpose of this study is to assess practice and factors affecting sun light exposure of infantsrnamong mother having infant in Debreberhan town in 2019. rnObjective: assess practice and factors affecting sun light exposure of infants among mothers in rnDebrebirhan town, North Showa, Ethiopia, 2019. rnMethods and Materials: Community based cross sectional study will be conducted to collectrnrelevant data among 665 mothers having infant at selected kebele in Debreberhan town .Arnsimple random sampling technique will be used to select kebele in the town and systematicrnsampling will be complemented to identify mothers having infant. The data will be collectedrnwith Interview using a pre tested structured and semi- structured questionnaire. Data will bernsummarized by using frequency distribution, proportions, percentages, and measures of centralrntendency. Binary and multiple logistic regressions will be used to examine association amongrndependent and independent variable. Statistical significance will be declared at p value less thanrn0.05. Ethical clearance will be obtained from Institutional Review Board (IRB) of Addis AbabarnUniversity, school of nursing and midwifery and participants of the study will be signed afterrngetting detailed explanation about the study from the data collector. rnWork plan: The study will be conducted from March 15 to April 15, 2019 rn Budget: The total budget require for this study is 28,358 Ethiopia birr