Objective      To study the expression of Nm23-H1 and its relationship with prognosis in patients with small cell lung cancer.       Methods      The expression of Nm23-H1 was detected by immunohistochemistry in 71 small cell lung cancer tissue samples and 22 normal lung tissue samples. According to their positive percentage and staining intensity

they were divided into 2 groups：high expression gro

up and low expression group. The correlation of Nm23-H1 expression with clinicopathology and prognosis was performed by SPSS 19.0.       Results      The positive rate of Nm23-H1 was higher in normal tissue samples than in small cell lung cancer（90.9% vs 57.7%，

P

0.05）；It was higher in limited stage than in extensive stage small cell lung cancer（66.7% vs 39.1%，

P

0.05）。 Multivariate logistic regression showed the Nm23-H1 expression was an independent protect factor for the metastasis of small cell lung cancer (OR=0.32

95% CI=0.12-0.90，

P

0.05). The subcellular location of the Nm23-H1 showed no difference between normal lung tissues and cancer tissues

neither between different stages. In the survival analysis

Nm23-H1 positive expression was found to be related with decreased median overall survival than negative expression patients (

P

0.05). The stage was also associated with mOS that the patients with limited foci stayed longer than those with metastastic diesease (HR=1.85

95% CI=1.03-3.63

P

0.05).       Conclusion      Nm23-H1 is midly expressed in SCLC cancer tissues

and mainly in the cytoplasma. The expression plays an important role in the metastasis of SCLC

and may be a predictive factor for the poor outcome of SCLC.