Focusing on the dilemma that high octane number gasoline blending was interfered owing to olefin reduction of FCC gasoline resulted in low octane number,the sensitivity of WK-602 octane number improver for various FCC gasoline fraction and interaction with other blending components were executed for the sake of laboratory evaluation. The experimental results show that WK-602 can effectively promote the gasoline octane number. The lower the octane number of fundamental gasoline,the more prominent the impact. RON can be enhanced proximately by 0.7~1 unit per increasing 0.5% additive dosage. Furthermore,such octane number improver has very favorable solubility with else high octane number components or additive without any negative effect. Industrial scale application indicates that WK-602 can homogeneously disperse when mixing with high octane number components or additives and obtained 97# motor gasoline can completely satisfy quality standards. Using WK-602 octane number improver to blend and produce 93 # and 97 # gasoline is very economical.