The Qualifications and Curriculum inquiry into the A-level reforms ordered by the Government will look initially at how schools have been affected by the new system.
Schools have complained of huge increases in both the number of exams and clashes of papers that have created an administrative nightmare as students sit up to five AS subjects.
And evidence provided by teacher unions and headteachers associations reveals that students and teachers have felt overloaded. They have also complained of reduced teaching time and the impossibility of fitting all the new courses into the timetable.
Key skills courses in maths, English and computer skills - for which sixth-formers must both put together portfolios and sit exams - have come in for paticular criticism.
Nigel de Gruchy, general secretary of the National Association of Schoolmasters Union of Women Teachers, warned: "Unless this top-heavy and confusing array of examinations is sorted out, pupils may think twice about entering the sixth form."
QCA chief executive David Hargreaves acknowledged that problems had arisen but said that there had been some schools who had had successful experiences this year.
He said the inquiry would investigate why some students and schools had coped with the new curriculum and exams and others had not. He also urged heads and teachers to provide practical suggestions on how to run sixth-forms better in future .
The second stage of the inquiry, will report in December. This will be a more wide-ranging review of all the Curriculum 2000 reforms, including AS-level, vocational A-levels and key skills.
It will take into account the outcome of this summer's exams. Many teachers have felt unable to predict results because they are unclear about where the grade boundaries lie and what level of difficulty "half-an-A-level" should be. There have also been concerns that vocational A-levels have been made too difficult in an attempt to make them comparable to academic A-levels.
Sir William Stubbs, QCA chairman, acknowledged the problems with the vocational exams. He said: "We will look at the relationship between vocational and academic A-levels, to ensure the demands on students are appropriate." He said the review would also look closely at the manageability of key skills courses.