To understand the situation of Streptococcus suis type 2 infection in Tibetan pigs from the Nyingchi region of Tibet,438 serum samples from the Nyingchi region were detected using double antigen sandwich ELISA,respectively. The result showed that the average positive rate of serum was 60. 05%,thereinto,the positive rates in Nyingchi county and Mainling county were 61. 79% and 57. 81%,and the positive rates in male and female pigs were 61. 50% and 60. 05%,respectively. There were no significant differences( ...