Objective To investigate serum brain natriuretic peptide (BNP) and sodium ions (Na+ ) levels in patients with febrile convulsions, and analyze their clinical role and significance. Methods 52 cases of febrile convulsions from April 2014 to October 2015 were selected for the study (FC group), another upper respiratory tract infection fever earlier but no seizures in children with fever 50 cases were selected as the control group (URI group), 50 cases of healthy children as healthy control group (control group), the serum levels of BNP and Na+ situation were compared. Results FC serum BNP levels were significantly higher than URI group and control group, Na + levels were significantly lower than the URI group and control group, the difference was statistically significant (P<0.05), two indicators of the level difference URI group and control group was not obvious, not statistically significant (P>0.05). There was a negative correlation (P<0.01) between serum BNP and Na+ levels. Conclusion Febrile convulsions serum BNP levels were increased, Na+ levels were lower with statistical significance, which may be related to BNP secretion of aldosterone inhibitory system and decreased serum sodium, will further promote the seizures. In a word, the serum BNP, Na+ the level have important clinical significance for their condition, treatment and prognosis.