The action of partitioning res communes is action of formation,but the segmentation judgment has the nature of formation judgment and payment judgment. The action has the nature of non-contentious matter,and it is called formal action of formation,but it is characterized by litigious trial. The particularity of the nature of the case will inevitably lead to many special rules in the trial procedure. In the action of partitioning res communes,if the co-owners conduct partitioning registrations on the same res communes,the res litigiosae of the two proceedings are identical,so they constitute repeated suits. In the case of real estates' merge split,it can be considered that the res litigiosae and the defense method are implicated,the res litigiosae is different,so the court should hear for the defendant's counterclaim substantively. When the co-owners reached a settlement in the proceedings,it should have the forming force and enforceability like referee split. The value of the object in contention is not a legislative fact,and the distribution principle of burden of proof should not be applied here. For the judge segmentation method,the application of the burden of proof should not be completely excluded. It is generally accepted that the plaintiff can appeal against the partitioning methods,and it means that the parties may appeal if it is possible for them to obtain a substantially more favorable court decision. Therefore,the view is not absolute that the court is not bound by the declaration of the plaintiff's partitioning method. The principle of adverse alteration prohibition is not applied in the action. Based on the implication of the right of claim for partitioning res communes and partitioning methods,the appeal effect of the co-owners shall extend to the full suit. Even if the defendant appeals only to the judgment of allowing partitioning and partitioning methods of the first-instance judgment,the court of appeal can also investigate and judge the collaborative segmentation registration and delivery of shares.