We have experimentally reported an ultrabroadband midinfrared (MIR) supercontinuum (SC) generation with high coherence property in chalcogenide tapered fiber with all normal dispersion (ANDi). The fibers, fabricated by an isolated extrusion method, made of Ge<sub>20</sub>As<sub>20</sub>Se<sub>15</sub>Te<sub>45</sub> core and Ge<sub>20</sub>As<sub>20</sub>Se<sub>20</sub>Te<sub>40</sub> cladding glasses. A homemade tapering platform allows us to accurately control the core diameters of the tapered fibers to realize ANDi characteristic. A coherent MIR SC spectrum spanning from 1.7–12.7 Μm was generated in a 7 cm long tapered fiber pumped at 5.5 μm. And high coherence property of the generated SC spectrum was investigated and verified by the simulation.