By using the VASP, we studied the magnetic and electronic properties of the monolayer lateral hetero-junction WS2-MoS2-nanoribbons (WS2-MoS2-NRs). Our results show that the NRs' edge chirality and width affect significantly its magnetic and electronic properties. The monolayer lateral hetero-junction ZZ-WS2-MoS2-NRs(ZZ:zigzag) exhibitmetallic behavior and have considerable magnetic moment. Their magnetic moments decrease in the order of N-z = 2, 6 and 4 (the width of NRs). While, the magnetic moment decreases with the increased r(z) (the number of the Mo-S chains, rz not equal 0 and r(z) not equal N-z) at the same width N-z. The N-A-AC-WS2-NR (AC: armchair) and N-A-AC-WS2-MoS2-NR-1 (the number of the Mo-S chain is 1) show metallic behavior when N-A = 3 (the width of NRs). The other monolayer lateral hetero-junction AC-WS2-MoS2-NRs remain the nonmagnetic and semiconducting behavior as bulk. But they are indirect band-gap except for the N-A = 3, r(A) = 2 (the number of the Mo-S chains) and N-A = 7, r(A) = 0 when N-A < 9. However they are direct band-gap when N-A >= 9. Their lowest and highest band gaps are 0.150 eV and 0.581 eV, respectively. These unique magnetic and electronic properties will provide guidanceon the WS2-MoS2 hetero-junction application in nanodevice. (C) 2016 Elsevier B.V. All rights reserved.