Permission For The New Created Login Name

I created a new login name. I checked 3 databases in User Mapping. I tried to mimic an existing login name. When I right clicked at the database and selected Properties. I selected the Permission tab at the left. It showed both login names under users or roles. I selected the existing login name and clicked the Effective Permissions button. The login has all permissions: Alter, Create, Select, Insert, Update, Delete, Execute, Connect, etc. When I selected the new login name and clicked the Effective Permission button, the login has only Connect. Why the new login name does not have all other permissions? And how can I assign to it?

Thanks.
DanYeung