The following experiments were conducted to explore the process of sentence comprehension by mentally retarded individuals. In EXP. 1 the acting-out technique and NP+NP+V sentences were used. In EXP. 2 the card-choosing technique and NP+NP+V sentences were used. The results indicated that: 1) the semantic strategy was frequently recognized in EXP. 1; 2) most of the subjects pointed to the actor on the card while the subjects chose one of two cards in EXP. 2; 3) subjects who used the word order strategy pointed to the item on the card according to both the semantic rule on the card and word order rule in the sentence. The hypotheses proposed to account for the results are as follows: The semantic strategy was found to be caused by moving the item; the word order strategy was in need of cooperation of attention to either an actor or an object, and attention to the first or second noun.