The total floor space of commercial housing sold by the developer amounted to 3.18 million square meters in January, down 28.5 percent from one year earlier, according to a statement the developer filed to the Shenzhen Stock Exchange.
Vanke is not the only property developer that reported falling sales. Evergrande Group, another major developer, saw its sales down 32.9 percent to 43.17 billion yuan.
The softening property sales suggest that the country's property market remains relatively cool. Chinese authorities have adopted a slew of measures to head off the risk of a property market crash, such as stiffening regulation and preventing high land prices.
Chinese leaders have reiterated on many occasions that "housing is for living in, not for speculation."
The average price of new homes in 100 cities rose 5.09 percent last year, a milder growth than 7.15 percent in 2017, according to a report issued by the China Index Academy, a property research institution, last month.
Meanwhile, secondhand homes in the country's 10 major cities saw their average price drop 0.11 percent, compared with an increase of 8.03 percent in 2017.