Abstract: The intelligent test-paper assembling is an important part of online education. Through the analysis of various performance indexes and constraint conditions in the process of intelligent test-paper assembling of online education，this paper established a suitable mathematical model of intelligent test- paper assembling. Based on the multi- objective optimization characteristics of intelligent testpapers assembling，this paper chose genetic algorithm to realize the intelligent test-paper assembling. With characteristic of intelligent test- paper assembling，this paper researched encoding，genetic operator and fitness function of test-paper.

Key words: online education, intelligent test-paper assembling, genetic algorithm