The zooplanktonic communities in Chilean inland waters are characterized by the high calanoid copepods dominante and low species number that is due to the oligotrophy and wide conductivity gradient. A view point in ecology is the null models use for determine that the community has not structural factors. The aim of the present study is analyze the zooplanktonic structure in three lakes of Aysen region with null models based in size overlap, with the aim of support or reject the traditional ecological results that described the presence of regulator factors in community structure. The results of size overlap revealed that the size structure is random, that is due to the absence of food resources limitation, interespecific competency absence and colonization and extinction population process.Keywords: zooplankton, communities, null models, Patagonia. RESUMENLas comunidades zooplanctónicas en aguas continentales chilenas se caracterizan por la alta dominancia de copépodos calanoideos y el bajo número de especies lo que se debe a la oligotrofía y alto gradiente de conductividad. Un enfoque de estudio de la ecología de comunidades es el uso de modelos nulos que consisten en demostrar que la estructura de la comunidad no está estructurada por factores reguladores. El objetivo del presente estudio es analizar la estructura zooplanctónica en tres lagos de la