This study aimed to examine the effectiveness of a program based on gamefication strategy in increasing learning-disabled preparatory school pupils' learning motivation and its effect on their achievement in Arabic Grammar. The sample consisted of (16) pupils with learning disability in Arabic Grammar, with age range of (12.8 – 13.9), and IQ range od (90 – 110). They were divided into an experimental group (8) pupils who received the training programme and a control group (8) pupils. It used Stanford-Benet Intelligence Test, Fast Neorogical Survey, Arabic Grammar Achievement Test, Learning Motivation Scale, and the training programme. Results showed that gamefication was effective in increasing the experimental pupils' learning motivation and improving their achievement in Arabic Grammar. Its effect continued after the follow-up period. Key Words: Arabic Grammar learning-disability, achievement, learning motivation, gamification Strategy.