Works by all the major artists of the Colourist movement are featured, including Peony Roses by S J Peploe, estimated at between £300,000 and 500,000.
The managing director of Bonhams Scotland, Miranda Grant, comments: "It is many years since there has been an auction of this depth and quality in Scotland".
Many of the Colourist works have been consigned from an overseas private collection.
They include Blue Studio George Street and The White Room by F C B Cadell, both estimated at £200,000-300,000 and Peploe's £200,000-300,000 valued Still Life with Flowers, Fruit and Fan.
At the Milliners, Paris by John Duncan Fergusson is expected to make between £180,000-250,000.
Peploe's £800,000-1.2m valued The Coffee Pot comes to auction at Christie's on May 26.