In vehicular delay tolerant network(VDTN),vehicles nodes often move frequently,which results in existing no end-to-end communication path between any nodes at a given moment,and VDTN has intermittently connectivity.The clock oscillators in the vehicle nodes are also susceptible to environment factors,and the crystal frequency fluctuates in the state of irregular.There exits much limitation and difficulty,when the traditional network clock synchronization algorithms are introduced directly into VDTN.A two-dimensional clock synchronization algorithm for vehicular delay tolerant network is proposed,which includes two synchronization processes in the vertical dimension and in the horizontal dimension.The two-dimensional clock synchronization algorithm reduces the time synchronization error and improves the synchronization accuracy,compared with the one-way synchronization.The experimental results show that VDTN obtains a higher synchronization accuracy through the two-dimensional clock synchronization algorithm.