Quang took over his new position at ceremony on Wednesday, where he pledged to do his best despite his relative lack of experience.
The Party Politburo had earlier decided that 52-year-old Quang will take the position vacated by Cang, 48.
Quang was deputy director of Tay Ninh Department of Planning and Investment and deputy chairman of the southern province before he became its Party Secretary.
In December last year, Cang was dismissed from several positions including deputy Party chief of HCMC, for his involvement in murky land deals.
Cang was held responsible for transferring land belonging to the Party unit, causing huge losses, and illegally approving a million-dollar property investment in the Thu Thiem new urban area.
Investigation found he had caused losses of over VND150 billion ($6.49 million) by letting a company under the HCMC Party unit sell cheap a 32-hectare (80-acre) riverside plot of public land in Nha Be District.
While serving as the city's Director of Transport Department, in 2013, he also approved a VND12.2 trillion ($524 million) investment by a property giant in the Thu Thiem area in exchange for 79 hectares of public land. Regulations at the time only allowed municipal administrations to approve projects worth up to VND1.5 trillion.