To investigate the influence of desiccation cracks on water infiltration patterns, iodine-starch staining experiments were carried out in cracked loamy clay soil. By application of the digital image processing technology and direct measurements, parameters including crack width, depth and area ratio of surface cracks were computed and employed to analyze the infiltration distribution influenced by crack geometric characteristics. The results showed that macro cracks whose width exceeded 1.25 cm could visibly accelerate water infiltration and provide obvious preferential pathways for water movement. Infiltration depths under macro cracks varied from 45 cm to 65 cm and there was no evident change in infiltration depth when the crack width increased, whereas micro cracks posed little effects on water infiltration. Water infiltration could be regarded as one dimensional semi-infinite homogeneous movement when cracks were narrow and shallow. On the contrary, deep cracks had significant impacts on infiltration, and obvious preferential features were observed around the macro cracks in soil. The results also revealed that area ratio of surface cracks was positively associated with the volume of wet soil (r=0.95), and a quantitative approach was proposed to assess the influence of soil cracks on water infiltration.