Clubbed wood cellulose nanocrystals ( WNC) were prepared via the acid hydrolysis of wood powders and were co-coagulated with natural rubber ( NR) latex to form a NR/WNC mixture.Then,the mixture was blended with butadiene-styrene rubber ( SBR) ,butadiene rubber ( BR) and carbon black ( CB) to obtain WNC /CB /NR/ SBR/BR composites,and the influence of the partial replacement of CB with WNC on the properties of NR/SBR/ BR blends was investigated.The results show that ( 1) as compared with the blends reinforced by 45 phr CB,the Payne effect of the composites with WNC weakens apparently,the processability improves obviously,the mechanical properties maintain well,the heat build-up decreases by 18. 4%,and the permanent set due to compression fatigue is generally lower than 5%; ( 2) the resistance to flex cracking of the composites filled with 5 ～ 10 phr WNC keeps constant,and the abrasion resistance of the composites filled with 5 phr WNC keeps consistent; ( 3) with the increase of WNC dosage,the loss tangent ( tan δ) value of the composites at 0℃ first increases and then decreases,while the one at 60 ℃ gradually decreases; ( 4) the temperature corresponding to 5% mass loss decreases,while that corresponding to the maximum mass loss rate changes slightly; and ( 5) the addition of WNC helps to maintain the aging performance of the composites.Moreover,SEM results demonstrate that the added WNC with a small quantity displays good homogeneity and strong interfacial interaction with the rubber matrix.