Materials and Methods: This research is a Double blind RCT. All of pregnant mothers with 26-34 weeks with signs of preterm labor have come to Alzahra & Talegani hospitals were research population. Research samples were 80 pregnant women that have eligibility criteria and treated with Sulphate mg & Nefidipin. Samples allocated randomly in 2 groups by use of rand list soft ware and block of 3 and 6.In group A were used Sulphate mg 4 g first and then 2g/h for 48 h and group B were used Nefidipin 20 mg first and 20 mg /half h after. Success of treatment was measured by Partograph & checklist .Data was analyzed by statistic tests and spss ver. 13.

Results: Neonatal complications such as 1 min Apgar and 5 min Apgar score, Sao2 and ABG in 2 groups, that treatment could not prevent contractions, have not significantly different. But there were significant different about Fetal complications such as bit to bit variation, decrease of fetal movement and dropt of base line of FHR (p≤ 0.05).

Conclusion: Data showed that Nefidipine was more effective in comparison of Sulphate mg in suppress of uterus contractions and improve of feto-Neonatal outcomes that these will prevent further Growth & Development complications in Neonatal and this drug can be best supplement for Sulphate mg in suppress of preterm contractions of uterus.