The high mobility of vehicles causes the frequent change of networks topology.This is part of a huge huge challenge on the data dissemination of VANETs.Even though existing flood-based routing protocols provide high reliability,they can not achieve the good trade-off shown among delivery ratio,delay,and the number of message redundant copies.A data dissemination scheme based on adaptive node density for VANETs is proposed. Nodes can rapidly gain the geographical distribution of“hotspot”regions via the proposed distributed algorithm. The hop-count limit function is established which is based on the Euclidean distance of the nearest“hostspot” region and density of nodes.When making forwarding deciding,nodes set a dynamically upper bound on the message hop count to avoiding unnecessary message redundant copies in the“hotspot”region.The number of message redundant copies can be effectively reduced in the network.The simulation results show that the delivery ratio and delay of this scheme are close to the epidemic routing protocol,but the number of message copies can be reduced by 37.5%.