Background: Diabetes describes a group of metabolic disorders characterized and identified by the presence of hyperglycemia in the absence of treatment. Objective: The aim of this study was early detection of renal affection in children with type 1 diabetes (T1DM) by using serumYkl-40 and high sensitivity C-reactive protein (Hs-CRP) as biomarker. Patients and methods: This study was a case control study carried out at Pediatric Department, in pediatric endocrine inpatient and outpatient clinic, Zagazig University Hospitals from October 2019 to October 2020. It included 57 participants collected from Pediatric Department in Zagazig University Hospital who were divided into 3 groups; each group included (19) patients.1^st group was diabetic group with normoalbuminuria (<30 mg/g creatinine), 2^nd group was diabetic group with microalbuminuria (30-299 mg/g creatinine), and the 3^rd group was healthy children. Results : The serumYkl-40 and Hs-CRP were good predictor markers for prediction of renal affection among children with T1DM with (86.8% and 94.7%) ability truly diagnose renal affection, (72.0% and 84.2%) ability to exclude truly negative ones and total (80.7% and 91.2%) accuracy for serumYkl-40 and Hs-CRP respectively.  Conclusion: YKL-40 and Hs-CRP levels could be used as tools to assess the risk of diabetic microangiopathy in the very early stage in T1DM patients.