Is there any way to create and modify entities/relationships without using LLBLGen Designer? Can I create my own cs-objects in my solution?(not in generated code) Any suggestions?

For what ORM framework do you want to do this? The designer helps you avoid doing manual labour, so it's in the general case more time consuming to do it by hand. If you want to use the keyboard instead of a mouse, you can use quickmodel (http://www.llblgen.com/Documentation/5.1/Designer/Functionality%20Reference/QuickModelEditor.htm), which is a text DSL inside the designer to quickly model entities. You can't beat that speed in code . What exactly do you mean with 'cs objects'?

Thank you for your answer! We want to use LLBLGen Pro runtime framework as ORM. My problem: In our system, on some UI page, user must be able to create and describe new Model in system ( = new table in database). And we must: 1 generate cs-code (entity) for Model, described by user 2 create table in database with properties, described by user 3 generate cs-mappings between table and cs-entity As a result, our system should work properly with new Model, I mean CRUD for new Model. So, in my situation i can't use Designer..

Conceptually, you can let the user define new tables in the database, but generating new model, what about building the code?

Basically, idea is: 1. user describes new Model 2. we generate cs-code - entity and mappings, we update DB 3. rebuild application 4. we can do CRUD with new model

That's not possible, you can't generate code at runtime, as that would require a license per user, sorry.