Mapping　building　plays　an　important　role　in　robot　navigation,　in　order　to　facility　agent　with　high　level　intelligence　and　mimic　the　major　function　of　rat＇s　space　cell,　a　new　mechanism　of　Genetic　Algorithm　Integrated　with　Neuralnetwork(GAIN)　was　proposed　in　this　paper.　Considering　the　scenario　of　unknown　environment　when　agent　explores　the　map,　weights　in　neural　network　remain　the　same　during　agent＇s　lifecycle　and　will　be　optimized　by　genetic　algorithm.　Several　simulation　was　performed　on　Unity　platform,　especial　the　Tolman　mouse　maze　experiment,　including　cross　position　learning　experiment,　spatial　orientation　experiment　and　roundabout　experiment,　had　been　reproduced　by　agent　other　than　real　rat.　Furthermore,　some　extension　of　experiment　has　also　done　to　further　prove　the　feasibility　of　the　algorithm.　Simulation　results　verified　the　proposed　GAIN　algorithm　can　endow　agent　with　cognitive　map　function.　©　2019　IEEE.