Thanks for your answer.

I use the latest version (preview 8) 

Everything is in French, but the PDF documents

The quotation screen is in french, with theese labels

Article 

Description 

Quantité 

Taxes 

Prix unitaire 

Sous-total 

Jour conseilJour conseil20,00020.01000,0020000,00

the PDF document

Description, Tax, Quantity, Unit Price...

In addition, the layout of document is very different to French habits, so I would like to change model... How???

Thanks for your help

You translate all from backend: Settings > Application Terms, Translated Terms.

Work a litte bit with filters...

Did you realy set the language of the partner to french?

The language of the odoo website / input mask / form depends on the odoo user language settings.

The language of the pdf reports depends on the recipient language settings.

>modify the template

The kind (rml, webkit, qweb) of the reports depends on your openerp / odoo version.

If use openerp 7 without webkit module, look at <openerp sever path>/openobject-addons/purchase/report/request_quotation.rml  you could change setLang(order.partner_id.lang)  to setLang("fr") with a text editor  >> NOT recommended<<