Procedure for the preparation of cationic guar having DS comprised between 0.01 and 3, soluble at basic pH and suitable for the use in the cosmetic field and in household cleaning products comprising the following steps: a) 100 parts by weight of guar flour are reacted with 3-chloro-2-hydroxypropyl trimethylammonium chloride and sodium hydroxide, in from 5 to 500 parts of a water and alcohol mixture containing from 20 to 50% by weight of water； b) the mixture is acidified to a pH between 4 and 6； c) from 2.2 to 3 parts by weight of glyoxal are added, and the reaction is stirred for approximately 30 minutes； d) from 300 to 1200 parts by weight of ambient temperature water are added and mixed for 10 to 90 minutes； e) the mixture is filtered under vacuum and the product dried to obtain glyoxalated purified cationic guar.
