In this paper, we investigate saturation performance of broadcast service in IEEE 802.11 based one-dimensional mobile ad hoc networks (MANETs) under multi-hop environment. Having analyzed the features of the multi-hop broadcast MANETs, for the first time we derive a closed form expression of broadcast packet reception rates, which is one of the important reliability metrics for broadcast communications. The analytic model takes IEEE 802.11 backoff counter process and hidden terminal problem into account. The proposed analytic model is validated by extensive simulations. From the obtained numerical results under various network parameters, new observations and potential enhancement suggestions are given.