英语翻译I went to your country's pevilon when shang hai Expro.

有问题...
"pevilon"应该是“pavilion”,指的是“中国馆”中的“馆”.
“上海世博会”是"ShangHai Expo".
所以,原句可以改成“I went to your country's pavilion in/during ShangHai Expo.”