This study examined the association of pregnancy with urolithiasis and provided new insights into urolithiasis in pregnancy.A total of 462 subjects were studied from January 2004 to December 2009 in Foshan Maternal and Child Health Hospital,China.Among the 462 subjects,162 cases of urolithiasis during pregnancy (UPG) were selected as the observation group,150 cases of no urolithiasis during pregnancy (NUPG) served as pregnancy control group,and 150 cases of no pregnancy (NPG) at reproductive age who took part in physical examination were randomly assigned into non-pregnant control group.At the same time,the patients in observation group were divided into the following sub-groups:no symptomatic urinary calculus (NSUC) and symptomatic urinary calculus (SUC) groups;SUC group was further divided into surgical intervention (SI) and conservative management (CM) groups.The general information and the data of blood and urine were collected and compared among the groups.The results showed that the incidence of urinary calculi in pregnant women was lower than that in non-pregnant women,the formation of urinary stone was associated with the change of metabolism of protein and sugar in pregnant women,and the surgical intervention was a practicable alternative to treat the clinical intractable symptomatic urinary calculi in pregnancy.