nginx redirect problem

[lhmwzy]

here is the conf:

    server {
        listen       10.68.150.4:82;
        server_name  h.test.com;
        root /usr/www;

        location / {
            index  index.html index.htm index.php;
        }

        error_page   500 502 503 504  /50x.html;
        location = /50x.html {
            root   /usr/local/www/nginx-dist;
        }

        location ~ \.php$ {
                fastcgi_pass unix:/tmp/php-fastcgi.sock;
                include        fastcgi_params;
                fastcgi_index  index.php;
        }
    }

I have a router in the front,and have set a port map

67.xx.xx.xx:8081-->10.68.150.4:82

But there is a problem
When I visit http://h.test.com:8081/house,the  redirected to
http://h.test.com/house/.
How can make it redirct http://h.test.com:8081/house/ when visit
http://h.test.com:8081/house?
TKS.