  We investigated the temperature evolution of crystal structure of
orthorhombic CoZr3, which is a superconductor with a transition temperature of
4.3 K, by synchrotron and laboratory (CuK{\alpha}) X-ray diffraction. Uniaxial
negative thermal expansion along the c-axis, which is similar to that observed
in tetragonal CoZr2, has been observed at a wide temperature range of T =
90-800 K in CoZr3, while a-and b-axis exhibit positive thermal expansion.
