The structure of the Au(110) surface was investigated in the temperature range between 60 and 1250 K by the ion channeling and blocking method using an electrostatic energy analyzer. An anomalous temperature dependence of the blocking pattern was found around 680 K which may be caused by a roughening transition. Above 770 K the number of visible atom layers increases faster with increasing temperature, as expected from the temperature dependence of the mean vibration amplitude