The popularity of Ethereum has fostered the emergence of money laundering. In traditional money laundering scenario, researchers have uncovered traits of money laundering. However, little is known about money laundering on Ethereum. To fill the gap, we conduct an in-depth study on Ethereum money laundering networks to explore whether money laundering on Ethereum has traditional traits. Specifically, we construct a money laundering network on Ethereum. Then, we present five questions based on the traditional traits. By leveraging network analysis, we characterize the money laundering network on Ethereum. In the end, we summarize the findings of money laundering networks on Ethereum.