A photosensitive polyimide composition; the composition comprises a base agent and a curing agent comprising a photoinitiator. By applying an aliphatic diamine monomer, which has a long carbon chain, and a grafting monomer, which has a main carbon chain having a double bond and an epoxy group at two ends respectively, to a method of making the base agent, a mixture of the base agent and the curing agent can be screen printed to form a photosensitive polyimide film on a copper foil. Also, the photosensitive polyimide film can be exposed under low exposure energy, and can be developed to a solder-resistant polyimide thin film by a weak alkaline developer after exposed. In addition, the solder-resistant polyimide thin film has low dielectric constant, low dielectric loss, good flame resistance, good solder resistance, and good pencil hardness. Accordingly, the photosensitive polyimide composition is applicable to high density flexible printed circuit boards.