A teaching assistant in Dongguan, Guangdong province, was detained on Wednesday on suspicion of lacing kindergarten children's food with antipsychotic medication.
On March 15, 10 pupils from Hongri kindergarten were hospitalized after showing symptoms of shock and excessive sleepiness following their meals.
All the victims have since recovered and will be discharged.
The suspect, a 49-year-old surnamed Yang, had worked at the kindergarten since September.
She had earlier requested a salary rise, which was refused, prompting her to leave her job briefly in February.
Police seized a bottle of antipsychotic medication that they found in Yang's home, which she told officers was for her own personal use.
Investigations are still ongoing.
