Gordon Jeyes says the attractiveness of a career among the ranks of the directorate can no longer be taken for granted. While Mr Jeyes did not focus on pay in a speech last week, the association has expressed concern in the past at the squeeze on salaries following the teachers' settlement which gave large increases to headteachers.
Heads of service, who are ranked just below directors, will often be paid less than the people they are managing.
In his speech to last Friday's local government conference on the great debate (page four), Mr Jeyes also says there is now a need to step up the professional development of the directorate.
"It would be sad if local educational leadership petered out not by rational choice and decision but through neglect, mistake and serendipity," he warned.