Abstract: The Nth-Powered P-persistent Broadcast protocol (NPPB) is a probabilistic broadcasting scheme, which is designed to alleviate broadcast storms and support effective emergency message disseminations in dense VANETs. In this protocol, a probability p is calculated by the receiver to decide whether it should rebroadcast or not. This method reduces the rebroadcast probabilities more efficiently, which can alleviate the serious competitions and collisions. Comparative analyses have been done in two aspects to compare the new NPPB with traditional schemes. And a saturated traffic jam scenario is established to evaluate the NPPB scheme. Simulations results show that if the value of n is selected appropriately, NPPB can achieve higher performance such as less delay, fewer hops, lower load and higher throughput, at the same time the reliability can be guaranteed.