There has not been racing at the track since Sunday's horse death. A horse named Arms Runner suffered a severe injury to his right front leg and had to be euthanized.
The accident occurred as Arms Runner and another horse crossed the dirt surface during the transition from the hillside turf course to the main turf course.
Animal activists have been protesting, calling for the track to cancel all racing.
Santa Anita Park sees 23rd horse death
Sen. Dianne Feinstein has also added her voice to those opposing reopening the track by writing a letter to the California Horse Racing Board on Tuesday, urging it to suspend all racing until all horse deaths are fully investigated.
For most of March, the park has been closed to racing due to several investigations, including one which inspected the entire track.
The reopening comes as the park gears up for its biggest race of the year, the Santa Anita Derby, scheduled to be held April 6.
There will be no racing on the hillside turf course, where the horse was fatally injured Sunday.
Eight races are scheduled to be held starting at 1 p.m.