Organic carbonyl compounds are regarded as the next-generation Na-ion competitors, but the high solubility into organic electrolyte and low electronic and ion conductivity limited their large-scale application. In this study, organic terephthalate potassium (K2TP) was newly introduced as an advanced anode for low cost Na-ion batteries. After in-situ synthesized with suitable graphene (25%wt), the as-prepared K2TP-25G nanocomposite can exhibit remarkable specific capacity of 135 mAh g−1 at 1 C over 200 cycles with stable capacity retention, which is superior to reported organic anodes for Na-ion batteries. The excellent electrochemical behaviors are ascribed to its stable and spacious lattice structure, the low solubility in common organic electrolyte of K2TP, as well as the formed K2TP-25G nanocomposite which can efficiently enhance the electronic conductivity and shorten the Na-ion pathway. These results are of importance to look insight into new organic electrode materials design for energy storage.