The micromilling tool is one of the key factors affecting micromilling performance. The design and fabrication of micromilling tools are still behind the increasing requirements in miniature component fabrication. How to estimate the fabrication accuracy of a newly designed micromilling tool is one of the urgent issues for micro tooling. This paper introduces an accuracy analysis method in the fabrication of micromilling tools by wire electrical discharge machining (WEDM) process. Taking two typical micro ball end mills into consideration, the micro tool fabrication process is kinematically modeled and analyzed. Analytical results show that the final fabrication accuracy has a close relationship with the designed micro tool geometry. The fabrication procedures can be arranged based on the kinematical analysis, and the final fabrication accuracy also is affected by it. The radius errors of the fabricated micro ball end mill prototype are within ${pm}2{mu}m$, which is higher than that of commercially available similar ones. It verifies the proposed accuracy analysis method.