Plaintiff shipyard and Defendant shipyard concluded several ship repair contracts for the three ships built by Defendant. Plaintiff performed all the ship repair obligations stipulated in each contract according to the contract, but Defendant defaulted on Plaintiff’s ship repair fee on the grounds that the ownership disputes of the three ships were tried by the court and the ownership was not clear (the court later made a judgment, and the ownership of the three ships was confirmed to be the third party in the case China Communications Construction). Plaintiff repeatedly urged Defendant to pay, and issued Property lien Notice to Defendant, and decided to lien the three ships under the actual control of Plaintiff, and after the notice was issued and the claim was still unsuccessful, Plaintiff filed an action before the court.