Abstract: The paper analyses the data of received Omega Signals from Gstation, at Xinxiang and Lanzhou respectively. It is worth especially noting that two receivers, which are adjusted in the optimum operating conditions, are used to simultaneously receive the signals at Xinxiang.The experimental results show that the measured phase cycle loss is a kind of propagation phenomenon during VLFsignal travelling. And together with the measurement result at Lanzhou, the reason for this phenomenon may be analysed forther.