Objectives To discover the depression status and salivary cortisol(SC)level among women with threatened preterm labor, and find their associations. Methods 138 pregnant women with threatened preterm labor were recruited in this study. Edinburgh Postpartum Depression Scale (EPDS) was applied to assess women's depression, and their saliva were collected at 8am, 16pm,23pm to test the cortisol level. EPDS≥9.5 was set as the cut-off value to assign the participants to depressive group(EPDS≥9.5) and non-depressive group (EPDS＜9.5). Independent samples t-test was used to compare the difference of salivary cortisol of the two groups, and Pearson correlation analysis was also applied to calculated the associations between depression and salivary cortisol. Results The average scores of EPDS in total women were (8.8±4.97). The incidence of depression (EPDS≥9.5) was as high as 46.4%.The average level of salivary cortisol at 8am,16pm and 23pm were(14.07±7.36) ng/mL, (9.27±5.03)ng/mL and (5.71±3.92)ng/mL respectively. EPDS in total women was associated with 8amSC(r=0.257, P=0.002) and 16pmSC(r=0.303, P＜0.001). EPDS in non-depressive group were also associated with 8amSC (r=0.306,P=0.008) and 16pmSC(r=0.203, P=0.048). Conclusion Women with threatened preterm labor have a high incidence of depression. There was a low-moderate level of association between maternal depression and salivary cortisol. Obstetrical doctors and nurses should focus on maternal psychological health level in women with threatened preterm labor. Even those individuals comparatively with a less severe depression, we need help them to minimize the severity of depression to achieve satisfying pregnant outcomes.