Synchronization of biological neuronal network is considered to play an important role in the processing of neuronal information in the brain. In this paper, a dendriticintegrated neuronal network (DHH) with spiketimingdependentplasticity (STDP) learning rule was studied, and the impact of network connection probability, external disturbance and STDP learning rule on network synchronization was analyzed. It was shown that the influence of STDP learning rule on network synchronization is related not only to connection probability but also to external disturbance. In the excitatory DHH neuronal network, the increase of connection probability could enhance network synchronization, and the increase of external disturbance could weaken network synchronization. In addition,the STDP learning rule has a weakening effect on the enhancement of network synchronization under large external disturbance. In the inhibitory DHH neuronal network, the increase of connection probability could also enhance network synchronization, and the increase of external disturbance could enhance network synchronization under large connection probability, while the STDP learning rule has a more obvious enhancement effect on network synchronization.