The Jockey Club says it is the largest single taxpayer in Hong Kong. According to the organization's website, it contributes 16.3 billion Hong Kong dollars ($2.1 billion), or 1.3%, to the gambling-mad territory's GDP.
"Our concerns are tied to potential social unrest in the vicinity tonight, the very real threat of a disturbance or possible violence at Happy Valley Racecourse, and uncertainty regarding transportation in and around" the area, a Jockey Club spokesperson said.
Protestors had earlier threatened to disrupt Wednesday's races, a night set to feature a horse belonging to pro-Beijing lawmaker Junius Ho.
It is the latest blow to Hong Kong's economy linked to a political crisis that has lasted for months. Pro-democracy protestors in the city have taken to the streets for 15 straight weekends.
One of the key problems today is that politics is such a disgrace, good people don't go into government.