Two-dimensional transition metal chalcogenides have diverse material species and physical properties, and their lateral and vertical heterostructures provide more freedoms to expand their applications in electronic and optoelectronic devices. Interfacial control, such as the interface structure, coupling strength and epitaxial size, is crucial for the heterostructure design. This paper was to develop an effective method to precisely control the in-plane heteroepitaxial interface structure, and reported the effective synthesis of the antiparallel MoS2-WS2 in-plane heterostructure. Based on the multi-scale characterizations, the lattice of the macroscopic antiparallel heterojunction is arranged parallelly in a microscopic scale, resulting in the seamlessly stitching of MoS2 and WS2 domains at their interface. MoS2-WS2 in-plane heterojunctions with the interface structures was further synthesized, paving an effective way for the precise interfacial control of two-dimensional material heteroepitaxy.