AbstractPulps were sampled from three major points of a deinking pulping line and classified as fibers fraction, fines fraction, and aqueous phase, respectively, then extracted with tetrahydrofuran (THF) or methyl tert-butyl ether (MTBE). Sticky contaminants in the extractives were examined by GC-MS analysis. The results showed that the contaminants can be grouped as adhesive substances, wood extractives, lignin-derivatives, and other organic acids, of which the adhesive substances were accounted as the major component. Contents of sticky components in each group and their removal were further evaluated according to the related unit operation. Adhesives remaining in fibers and fines fractions were removed by the post-flotation. Wood extractives and degraded residual lignins were also released to some extent from pulp fibers during heat-dispersing, and then removed during the post-flotation.