Memristors　based　on　organic-inorganic　halide　perovskite　have　received　intensive　attention　because　of　its　solution-processability　and　defect-tolerant　characteristics.　But　the　lead　element　in　perovskite　is　inevitably　harmful　to　human　body　and　environment.　Herein,　we　report　an　e-synapse　based　on　lead-free　organic　halide　perovskite　(CH3NH3)3Sb2Cl9　(MA3Sb2Cl9),　which　exhibits　excellent　mimic　of　biological　synaptic　characteristics,　such　as　excitatory　postsynaptic　currents　(EPSCs),　inhibitory　postsynaptic　currents　(IPSCs),　and　paired-pulse　facilitation　(PPF).　Furthermore,　the　synaptic　weight　of　the　e-synapse　is　found　to　be　dependent　on　the　frequency　of　pulse　stimulation.　The　charge　conduction　mechanism　of　the　e-synapse　is　proposed　based　on　the　in-depth　investigation　of　the　electrical　characteristics　of　the　devices.　This　work　demonstrates　that　lead-free　organic　perovskite　MA3Sb2Cl9　provide　a　new　perspective　on　engineering　e-synapses　for　neuromorphic　computing　and　have　a　great　potential　for　environment-friendly　artificial　intelligence　applications.　©　1963-2012　IEEE.