Split 2 plan

[Avarax]

Hi. How can i connect 2 ship in space center. I build a rover and next plan have rocket . 

[diomedea]

Believe you mean how to have the rover connected to the other vessel in editor (VAB/SPH).

1) build your rover, to include the part that will attach to the other vessel (docking port? separator?)

2) change the root part of your rover to that part going to connect (use the re-root gizmo in editor, 4 key)

3) save the rover as a subassembly (in editor, enable advanced mode, clicking the most top-left arrow button; find and click the subassemblies icon, then click on the root part with the rover and drag to the "subassembly drop zone", you'll be required to enter a name/description and the rover will be saved as a retrievable subassembly)

4) build your other vessel, planning for space where to insert the rover. If required by your design, have the corresponding connecting part (e.g. docking port)

5) re-open the subassemblies tab in editor, click on the saved rover subassembly, and bring it to connect where intended (Note: the editor will rotate the rover to face the same direction of the root part in your vessel, which isn't always what you would do, so use the rotation keys to align properly)

[Avarax]

thx

[Aegolius13]

Another option is: on the load menu in the VAB/SPH, there should be a button that says "merge."  This will put the entire loaded craft in the VAB/SPH, along with whatever craft you had open.