The patterning of conductive films in a traditional way involves photolithography process that consists of multiple steps like developing, etching, etc., and thus is time consuming, complex in constructing functional layers of devices, and expensive. Inkjet printing, a non-vacuum, non-contact, mask-free, low-cost, high-flux, precise and convenient desktop deposition technology, can be adopted to ... [Show full abstract] directly metallize conductive lines with relatively less materials and time, and shows increasing application potential in the fabrication of flexible and large scale display electronics. The development of high-performance and environmental-friendly conductive inks, which require non-toxicity, low-temperature sintering and high conductivity, is one of the main obstacles to fabricating flexible electrodes by inkjet printing. Organic materials, such as polyaniline and PEDOT/PSS, are previously chosen as printable conductive precursors due to its favorable solution processability, but they are poor in conductivity and chemical, thermal and electrical instability. Compared with other conductive materials, silver nanoparticles which are gifted with high conductivity, anti-oxidation, stability and rational price have provoked considerable research interest in the field of printable electrical devices, and have already achieved commercialization. On the other hand, the continuously increasing demands of electronic devices for low cost, low energy consumption, high yield and flexibility exaggerate the significance of both environmental friendliness and low-temperature sintering in the developing of nano-inks besides the high product performance. Recently, apart from the optimization of ink system, e.g. developing green and water-soluble inks, researchers also showed passion for novel low-temperature sintering techniques in order to achieve green, low-temperature and high conductivity printable inks. In a traditional thermal sintering condition, the resistivity of 6.6 μΩ•cm can be obtained by sintering a silver nanoparticles (SNPs) ink with Lauric acid as dispersant and NaBH4 as reducing agent at 125℃, while the silver-organic complex (SOC) ink with ammonia as complexing agent and HCOOH as reducing agent can achieve the resistivity of 1.6 μΩ•cm by adopting 90℃ sintering temperature. The novel sintering techniques are conducive to overcoming the limitations of the inkjet printing process and low temperature sintering (<100℃) of high performance (<6 μΩ•cm) inks. Aqueous silver ink contributes to the attenuation of toxic waste emissions, and possesses higher stability than organic ink when using polyelectrolyte as dispersion agent, and thus is applicable for mass production. This paper offers an introduction of aqueous SNPs suspension and SOC solution, both of which can serve as aqueous silver ink, gives comparative analysis for the ink systems with different dispersants, complexing agents, reducing agents and aggregation modes, and summarizes the representative novel low-temperature sintering techniques including chemical sintering, vapor reduction sintering, hot-water-assisted sintering and photo-induced reduction sintering. These optimized ink systems and sintering methods can facilitate to impart high performance, high stability and flexibility to conductive inks, and will promote to a large extent the innovation with respect to flexible low-temperature ink pro-ducts and flexible printing electronics.