A study of magnetic parameters was carried out on a Late Pleistocene and Holocene sedimentary sequence (5 m) from Lake Manas (northern Xinjiang, China), that has already been analyzed for bulk sediment mineralogy, stable isotopes from carbonates and biogenic material. Magnetic minerals confirm major changes in palaeoenvironmental and palaeohydrological conditions that were deduced from other methods. They also provide complementary information on changes in the lake system during the early and middle Holocene. The most important mineral magnetic change results from the authigenic formation of ferrimagnetic greigite, Fe3S4 during the lacustrine episodes dated from ~8.7 kyr B.P. to ~5.5 kyr B.P. (380--335 cm) and from ~4.5 kyr B.P. to ~3.5 kyr B.P. (320--285 cm) respectively. Our data also indicate an abrupt break in sedimentary conditions which coincides with a short-term return towards dry climatic conditions around 3.5 kyr B.P., which was only suggested from other proxy data. ¿ American Geophysical Union 1995