Import users from a CSV file into WordPress
Click on the 'Import From CSV' link in the 'Users' menu, choose your CSV file, choose if you want to send a notification email to new users and if you want the password nag to be displayed when they login, then click 'Import'.
Each row in your CSV file should represent a user; each column identifies user data or meta data. If a column name matches a field in the user table, data from this column is imported in that field; if not, data is imported in a user meta field with the name of the column.
Look at the example.csv file in the plugin directory to have a better understanding of how the your CSV file should be organized. You can try importing that file and look at the result.