目的　通过对广东省 90年代以来流行的登革病毒分子流行病学研究 ,初步了解我国毒株的可能来源。方法　采用RT PCR方法扩增广东省不同年份分离的登革病毒 (DEN) 1型和 2型NS1部分基因片段 ,然后进行克隆测序。测序后的基因片段与国际上已知的多个DEN1和DEN2相应的序列进行比较 ,并以核苷酸的差异在 6 %以上作为基因亚型分型的标准。结果　①广州 1991年分离的DEN1(GD0 3/91)与潮洲 1995年分离的DEN1(GD2 3/95 )同源性很高 ,为 97% ,属同一基因亚型 ,而两者与从潮洲 1997年分离的DEN1(GD14/97)同源性均为 93% ,分属不同的基因亚型。基因系统树分析提示 :GD0 3/91和GD2 3/95可能来自东南亚或瑙鲁等地 ,GD14/97可能来自新加坡。②佛山市 1993年分离的DEN2 (GD0 6 /93)和南海市 1998年分离的DEN2 (GD0 1/98)同源性为 93% ,分属不同的基因亚型。基因系统树分析提示 :GD0 1/98与泰国流行株ThNH P2 8/93株共享序列非常接近 ,核苷酸同源性为 98% ,氨基酸同源性为 10 0 % ,因此推测GD0 1/98可能来源于泰国。结论　广东省 90年代以来流行的登革热来源于不同的传染源。 Objective To understand the molecular epidemiology of dengue virus in Guangdong Province since the 1990s, so as to understand the possible sources of the strains in our country. Methods Partial gene fragments of dengue virus (DEN) type 1 and type 2 NS1 isolated in different years of Guangdong were amplified by RT-PCR and cloned and sequenced. The sequenced gene fragments were compared with the corresponding sequences of several known DEN1 and DEN2 in the world, and the nucleotide subtypes were classified according to the nucleotide difference of more than 6%. Results ① The DEN1 (GD0 3/91) isolated from Guangzhou in 1991 had a high homology of 97% with DEN1 (GD2 3/95) isolated in Chaozhou in 1995, which belonged to the same genotype. However, In 1997, DEN1 (GD14 / 97) isolates shared 93% homology, belonging to different genotypes. The phylogenetic tree analysis suggests that GD0 3/91 and GD2 3/95 may come from Southeast Asia or Nauru and GD14 / 97 from Singapore. ② The homology between DEN2 (GD0 6/93) isolated from Foshan in 1993 and DEN2 (GD0 1/98) isolated from Nanhai in 1998 was 93%, belonging to different gene subtypes. The phylogenetic tree analysis suggested that the shared sequence of GD0 1/98 with the ThNH P2 8/93 strain of Thailand was very close, with nucleotide homology of 98% and amino acid homology of 10%. Therefore, we speculated that GD0 1/98 May come from Thailand. Conclusion The prevalence of dengue fever in Guangdong since the 90s originated from different sources of infection.