To　investigate　the　effects　of　MR　prenatal　exposure　on　the　ability　of　learning　and　memory,　we　examined　the　behavior　changes　of　rats　after　treatment　and　its　molecular　mechanism.　Fourteen　pregnant　Sprague-Dawley　rats　were　randomly　divided　into　an　experimental　group　and　a　control　group,　each　with　7　mother　rats.　The　experimental　animals　were　exposed　to　MR　between　days　12　and　18　of　gestation　for　10　min　a　day.　After　birth,　all　male　litters　were　randomly　divided　into　an　MRI-scanning　group　(experimental　group)　and　a　control　group.　And　Morris　Water　Maze　(MWM)　tasks　were　tested　at　1st-,　2nd-　and　5th-　month　after　birth.　The　results　showed　that　the　MR　exposed　rats　at　the　age　of　2　months　spent　less　time　than　the　non-exposed　ones　in　the　platform　quadrant　during　probe　trial　test,　means　a　minor　＂reference　memory＂　deficit　for　the　treatment　animals.　Then　the　2　months　groups　were　selected　for　microarray　and　Western　blot　to　detect　the　molecular　mechanism　of　behavior　deficit.　Here　we　found　that　only　12　genes　among　all　the　tested　were　up　or　down-regulated.　Western　bolt　showed　that　CaMK　II　beta　was　changed　significantly.　We　suggested　that　the　potential　impairment　of　spatial　learning　and　memory　induced　by　prenatal　MR　exposure　was　aged　dependence,　which　may　mediated　by　regulation　of　CaMK　II　beta.