can I exhange body parts from a model with another an then add the figure to library in poser ?
thx for teaching!!

Sort of... You can bring a prop into the scene and replace a bodypart with it... so you could take the part of the model that you want to "graft" onto the main figure, and bring it into the scene as a prop (You may have to export it from the first model, then reimport it into the scene with your second figure), position and scale it so that it's where, and the size you want it... I'm not sitting in front of Poser, so I'm not sure exactly where it's at, but either someone here will know, or you can check the manual, but there's a menu somewhere that has an option for "replace body part with prop" or something to that effect... That's what you want... it'll replace the body part in question with the prop you select... now you can get into some weird joint issue when you pose the newly grafted body part, but sometimes it works out just fine... You can then save you hybrid figure to your figures library like you normally would...

thanks for Cin's teaching , and I think I still have a question. if I export a part from the figure and import as a prop, I will lose all those morph, just like I want to exchange the head of a human , if I use your method, I can't make out a smlie face anymore... so is it possible that keeping the morph? thx teaching !

I'm sure there are other ways of doing it that would be easier, I just don't know them... but you could export each morph target from your original and add it back into your new figure.

The was a pretty good tutorial at morphworld on adding limbs to a figure, might work for what you're wanting to do.