It is to improve the welfare of horses
The Grand National will be reduced from 40 to 34 runners from next year to improve the welfare of horses.
Three animals in April's field died after sustaining injuries in the famous race at Aintree.
The 5-15 start time will also be brought forward so that they get the best of the course conditions.
It's the first time since 1984 that the maximum field size will be cut.