The effects of fiber factors, such as kind of fiber, fiber volume fraction, fiber diameter, fiber length, and geometric shape of fiber on the plastic shrinkage cracking of the cement mortar were investigated. The testing results indicate that different kinds of fibers show different effects on the plastic shrinkage cracking; the total weighted cracking value will increase with the fiber volume fraction; the smaller the fiber diameter and the longer the fiber length, the higher the abilities of anti-plastic-cracking will be. Different geometric shapes will produce different influences on the ability to resist the plastic shrinkage cracking of cement mortar.