Abstract: To evaluate the urinary hydroxyproline:creat inine ratio (THP/Cr) for the diagnosis of Rickets, the urinary THP/Cr was measured in children with rickets and normal children.The results showed that urinary THP/Cr was elevated in children with rickets, The correlative analysis showed that there was a negative correlation between the urinary THP/Cr and the serum 25(OH)D3.There was a postive correlat ion between the urinary THP/Cr and the serum ALP.The above results demonst rated that urinary THP/Cr may serve as a diagnostic indicator in rickets.