It blames poor liaison between education and social services departments and calls on the Government to issue clearer guidance to councils and schools.
The findings are based on responses from 114 of the 150 English local authorities to a study by the National Society for the Prevention of Cruelty to Children. Seventy-seven per cent felt primary children could be protected. This figure dropped to 68 per cent for secondary pupils.
Less than half (47 per cent) believe the system can protect primary pupils in need of better parenting, with the figure falling to 42 per cent for secondary pupils.
And Mary Baginsky, a senior researcher at the NSPCC, said although 73 per cent of local authorities provided some training, in most cases it was ad hoc.
She said: "It amounted to little more than briefing sessions at meetings for headteachers or designated teachers."
She recommends appointing a dedicated person in each authority to deal with child protection, and wants a national child protection training strategy for anyone working in schools.
Councils do not have a statutory responsibility for private schools, but 76 per cent felt they did have some responsibility. More than half (54 per cent) had provided training for private schools and 46 per cent said they would be prepared to support an independent school making a child protection referral to social services. One in five (20 per cent) also ensured that private schools had written policies on child protection.
* The report follows the launch of a pilot NSPCC project into domestic violence in schools in West Sussex. Teachers are provided with support packs telling them how to spot pupils who could be experiencing domestic abuse. Common behaviour includes increased anxiety and illnesses including headaches, abdominal complaints, stuttering, withdrawal and fear.
"Responsibility Without Power" costs pound;7.50 and is available from the NSPCC at www.nspcc.org.ukinform Letters, 21 Governors, 23