目的分析中国广东籍人β纤维蛋白原Ｇ／Ａ４５５（βＦＢＧ４５５Ｇ／Ａ）基因多态性，计算各型的基因频率，测定不同基因型人血浆纤维蛋白原（ＦＢＧ）水平，探讨该基因多态性与基因表达的相关性。方法应用聚合酶链反应限制性酶切分析方法，分析２１０名广东籍人ＤＮＡ样品的βＦＢＧ４５５Ｇ／Ａ多态性，比浊法测定其中９２名血浆ＦＢＧ水平。结果βＦＢＧ４５５Ａ／Ａ纯合子８名，基因型频率为０．０３８；βＦＢＧ４５５Ｇ／Ｇ野生型１０８名，基因型频率为０．５１４；βＦＢＧ４５５Ｇ／Ａ杂合子９４名，基因型频率为０４４８。Ａ等位基因频率为０．２６２。４６名Ｇ／Ａ型血浆ＦＢＧ水平为（２．１８±０．２４）ｇ／Ｌ，４２名Ｇ／Ｇ型为（２．０３±０．２５）ｇ／Ｌ，两组比较差异有显著性（Ｐ＜０．０１）。结论中国广东籍人群中βＦＢＧ４５５Ａ等位基因频率比欧洲一些国家高（Ｐ＜０．０１）。Ｇ／Ａ型血浆ＦＢＧ水平比Ｇ／Ｇ型高（Ｐ＜０．０１）。提示该基因位点多态性与血浆ＦＢＧ的表达有一定相关。 Objective To analyze the polymorphism of βFibrinogen G / A455 (βFBG455G / A) gene in Guangdong of China, calculate the gene frequency of each type, and determine the level of plasma fibrinogen (FBG) in different genotypes , To explore the relationship between gene polymorphism and gene expression. Methods PCR-restriction analysis was used to analyze βFBG455G / A polymorphism in DNA samples from 210 Guangdong native people. 92 plasma FBG levels were determined by turbidimetry. RESULTS: Eight β-FBG455A / A homozygotes had a genotype frequency of 0.038, 108FBG455G / G wildtype (108), genotype frequency was 0.514, βFBG455G / A heterozygote 94, the genotype frequency of 0  448. The frequency of allele A was 0.262.46 (2.18 ± 0.24) g / L for G / A type plasma and (2.03 ± 0.25) g for 42 G / G type / L, the difference between the two groups was significant (P <0.01). Conclusions The frequency of βFBG455A allele in Guangdong population in China is higher than that in some European countries (P <0.01). G / A plasma FBG levels were higher than G / G (P <0.01). It is suggested that the polymorphism of this gene is related to the expression of FBG in plasma.