It is understood that the agency has not found a replacement for her post.
Ching joined Zenith China in January 2008. She was previously MD of ZenithOptimedia Japan for six years, and subsequently worked for Publicis Groupe in Shanghai, including a stint as regional account director in Singapore.
News of Ching's departure comes after a number of senior management changes at Zenith Media China in the past few months.
Optimedia's North China MD Polun Ip resigned in February after ten years with the network in China. The agency did not replace the MD role but instead appointed Brenda Liou as GM.
Ada Wong joined ZenithOptimedia Guangzhou to the newly created position of MD in January, following GM Stephanie Li's resignation after seven years with the agency in November 2010.
Gary Sin also came on board to replace Alan Yau as MD of Zenith Media Shanghai in November 2010.
At the time of press, Zenith China could not be reached.