先安装nginx的yum源，http://nginx.org/en/linux_packages.html#stable 找到链接，安装：
rpm -ivh http://nginx.org/packages/centos/6/noarch/RPMS/nginx-release-centos-6-0.el6.ngx.noarch.rpm

查看：
yum info nginx

安装：
yum install nginx

运行
service nginx start