The MoS2/graphene composites were synthesized by a hydrothermal route in the presence of graphene oxide sheets with assistance from poly(diallyldimethylammonium chloride) (PDDA). The results of characterizations show that the MoS2/graphene composites exhibit a graphene-like morphology with interconnected network, in which single- or few-layer MoS2 sheets are homogenously dispersed and well anchored on the graphene surface. The robust heterostructure and morphology of MoS2/graphene composites can not only provide more sites and channels for lithium ion accommodation and diffusion, but also facilitate electrolyte access. The heterostructure also maximizes the synergistic effects between MoS2 and graphene. Therefore, MoS2/graphene composites exhibit significantly improved electrochemical performances for reversible lithium storage. In particular, the MoS2/graphene composite prepared with monomer concentration of PDDA being 0.02molL−1 exhibits a reversible capacity of 1100mAhg−1 with enhanced rate capability. The reversible capacity of 856mAhg−1 after 900 cycles at 500mAg−1 can be remained, indicating its excellent cyclic stability.