This paper deals with the antiseizure properties of connecting rod bearing for which the overlay is worn due to extended engine operation.Trimetal bearings from operating engines were collected and their surface condition was evaluated. It was found that there were some bearings where the Ni-compound layer had been exposed. For such bearings the seizure-load-limit was lower than that for bearings whose overlay was still intact.In order to understand this tendency quantitatively, the effect of the bearing materials on anti-seizure properties were studied. Using these results, the authors analysed the correlation between bearing seizure and some parameters which can estimate the work load of the bearing. It was found that the “mean unit load of the bearing X velocity” can serve as a practical parameter for bearing seizure.