目的　了解我国间日疟原虫MSP1(PvMSP1)的等位基因类型和序列的多态性。方法　用特异的引物通过套式PCR方法体外扩增包含PvMSP1的ICB5与ICB6之间的基因片段 ,并对部分扩增产物进行序列测定和分析。结果　 2 7份间日疟原虫患者血样中 ,有 16份 (5 9 9% )扩增得到Belem型基因产物 ,2 5 (92 6 % )份扩增出Sal- 1型基因产物 ;两种不同等位基因型虫株的混合感染率为 5 1 9%。序列分析结果发现一个以前未见报告的基因内重组类型。结论　我国间日疟原虫虫株存在两种PvMSP1等位基因型 ,Sal- 1型可能是主导型 ;不同等位基因型的混合感染率较高 Objective To understand the polymorphism of allele type and sequence of Plasmodium vivax MSP1 (PvMSP1) in China. Methods The gene fragment between ICB5 and ICB6 containing PvMSP1 was amplified by nested PCR method using specific primers. The amplified products were sequenced and analyzed. RESULTS: Belem-type gene products were amplified from 16 of 7 (59.9%) blood samples and 25 (92.6%) of Sal-1-type gene products were amplified in 2 7 blood samples from patients with Plasmodium vivax. Two different The mixed infection rate of allelic strains was 51.9%. Sequence analysis revealed a previously unrecognized intragenic recombination type. Conclusion There are two PvMSP1 alleles in Plasmodium vivax strains in our country. Sal-1 type may be the dominant type. The mixed infection rate of different alleles is high