中文摘要：

为了了解禽流感的生物学特性和遗传进化规律,有效防治禽流感疫情,本试验从河南省洛阳地区发现疑似H9亚型禽流感的病死鸡中分离得到两株病毒（LYPLK1和LYPLK2）,经鉴定为H9亚型禽流感病毒,通过RT-PCR方法扩增其HA基因进行序列分析。结果分离株属于H9亚型禽流感欧亚系Y280/97分支,并发生了一定的变异。

英文摘要：

Samples of suspected H9 subtype avian inflenza illness chickens were collected from Luoyang in Henan province,and two virus strains（ LYPLK1 and LYPLK2） were isolated. The HA gene of them were amplified by RT-PCR method and sequenced. Sequence analysis showed that the two isolated belonged to H9 subtype of avian influenza Eurasian Y280 /97 branches,and a certain variation.