A calligraphic album written in xingshu (cursive) style by Qianlong will be auctioned, too. It was listed as a Shiqu Baoji entry. The emperor completed the leaves at age 61, when he was considered to have achieved mastery in calligraphy.

The two works are among dozens of quality lots to feature in Guardian's "Grand View" night sales of Chinese painting and calligraphy. The sales offer many rarely seen pieces expected to fetch mind-blogging prices. A painting of modern master Pan Tianshou grossed 279 million yuan in a similar sale in May.

Pan's two large paintings, Pine Trees and Morning Glows, will also highlight the upcoming sales. The former shows the master's excellent control of composition, and the latter tells his powerful response to a saying that "classic Chinese paintings were embracing nihilism" in the 1960s.

"Grand View" sales are widely seen as the barometer of the Chinese painting market. The art market has turned sour in the past few months because of the country's economic slowdown. Several collectors and dealers anticipate that upcoming "Grand View" sales, with several celebrity works like Pan's on offer, will boost the art market.

Guo says under the current situation in which collectors are less willing to sell or buy, some auctioneers try to bring people back to the salesroom by selling at rather cheap rates, but she says the strategy wouldn't work for long.

"This is because when the market goes down, buyers become quite picky and prefer saving their money for top-notch artworks, especially the rare ones.

"Categories that interest only a small group of collectors and are priced moderately, such as calligraphic rubbings from tablet inscriptions, are also well received in the market," she says.