Abstract: Objective To investigate the expression of long non-coding RNA （lncRNA） maternally expressed gene 3 （MEG3） and growth arrest-specific transcript 5（GAS5） in serum of patients with multiple myeloma and their clinical significance. Methods A total of 87 patients with multiple myeloma admitted to our hospital from January 2014 to January 2016 were selected as the study subjects，and 54 healthy volunteers were selected as the control group. The expression levels of lncRNA MEG3 and lncRNA GAS5 were detected by real-time quantitative reverse transcription polymerase chain reaction（qRT-PCR），and their relationships with clinicopathological data and prognosis of patients were analyzed. Results The levels of serum lncRNA MEG3 and lncRNA GAS5 in multiple myeloma patients were lower than those in the control group（5.92±0.87 vs 9.13±1.26，t=17.882，P<0.001；4.27±0.51 vs 8.26±1.04，t=30.417，P<0.001）. The expression levels of them were selected correlated with age，D-S stage，number of malignant plasma cells，β2-MG level and hemoglobin content（P<0.05）. The 3-year overall survival rate of the low-expression group of MEG3 and GAS5 were lower than those of the high-expression group of MEG3 and GAS5（32.56% vs 56.82%，χ²=5.617，P=0.018； 32.43%  vs 52.00%，χ²=5.389，P=0.020）. Low expression of MEG3 and low expression of GAS5 were associated with poor prognosis in patients with multiple myeloma（HR=3.503，95%CI：1.517-8.091；HR=3.319，95%CI：1.438-7.661）. Conclusions lncRNA MEG3 and lncRNA GAS5 are lowly expressed in serum of patients with multiple myeloma，which are related to the poor prognosis of the patients. 

Key words: Multiple myeloma, Long non-coding RNA, Maternally expressed gene 3, Growth arrest-specific transcript 5, Prognosis