Based on the tunnel environment and the characteristic of flammability and explosion of liquefied petroleum gas (LGP), the leak of LPG tanker can induce heavy casualties and property loss in the tunnel. In order to study quantitative risk of LGP transportation in road tunnel, the data of 599 accidents and 659 accidental vehicles are collected. From these data, the proportion of LGP tanker accident in the total accident vehicles and million vehicles kilometer (MVK) tanker accident rates are obtained. By analyzing the leakage scene of LGP tanker, the possible accident types of the LGP transportation were analyzed, such as boiling liquid expanding vapor explosion (BLEVE), vapor cloud explosion (VCE), flash fire and jet fire, etc. The impact of leak time to various ranges of injury is studied in the condition of LGP continued leakage. The slight injury, serious injury and death radius of LGP leakage accidents are calculated in tanker loaded with different LGP quantity. In view of the accidental analysis, the countermeasures will be proposed to reduce the risk of LGP transportation in road tunnel.