The rheological properties of carbon black gel ink were determined. The relationship between the rheological properties and the performance of writing and storage stability of the gel ink was investigated. The results showed that carbon black gel ink was shear thinning with a power of 0.3—0.6. Carbon black gel ink imported from Japan matching for needle shaped pen nib is viscous fluid, while that for bullet shaped nib is viscoelastic. The storage stability of ink for 150 d predicted by dynamic time sweep is agreed with that predicted by shear stress sweep. Structure stability is the key way to understand the storage stability of carbon black gel ink.