In order to improve the application performance of C. I. Pigment Yellow 155，C. I. Pigment Yellow 155 crude was obtained by diazotizing 2-amino-dimethyl terephthalateand then coupling with 1，4-diacetoacetyl p-phenylenediamine. It was treated with organic solvents（DMF and NMP）， as well as hydrothermal treatment. Then，C. I. Pigment Yellow 155 samples were obtained. The color performance，crystal form，thermal resistance，contact angle，and particle size were measured. The results showed that after the pigmentations withDMF and NMP，the crystallinity of C. I. Pigment Yellow 155 crude was improved，the particle size was reduced，the particle distribution was narrower，the coloring strength was up to 109. 9%，and the hydrophobicity increased.