To provide a latently crimpable polyester conjugate fiber that does not intrinsically include uneven thinning caused by abnormal polymer extrusion on the melt spinning, and has reduced unevenness in fluff or the like and a desirable degree of whiteness.

Two kinds of polyesters having a difference in intrinsic viscosity in the range of 0.1-0.4 are combined with each other into a side-by-side or eccentrical sheath core structure. In this case, the two kinds of polyesters are produced through the polycondensation reaction in the presence of a catalyst prepared by the reaction between a specific titanium compound and a phosphorus compound.