Soil cracking is governed by the change in effective stress during the tensile process. To analyze the mechanism of soil cracking, pore pressure measurement during soil tensile test is necessary to evaluate the effective stress. In this study, to measure the pore pressure at the location in front of soil fracture, we utilize a miniature fiber optic water pressure catheter. A series of tensile tests is conducted on compacted saturated clay specimens with different water content and the fiber optic sensor is used to measure the pore pressure as the soil fracture propagates. The pore pressures at different locations relative to the crack position are measured in order to evaluate the change of matrix suction along with the development of the plastic zone formed in front of soil crack.