Abstract : Immaterial assets are traditionally described either as intangible assets or as intangible or intellectual property, or else as operating assets, but most of those terms are not satisfactory. This class of assets actually suffers from a lack of definition. However, some people state that they represent a form of economic wealth, a fantastic source of credit for the debtors, and a guarantee of safety for the creditors. And yet, French legislation seems to have ignored immaterial assets.This is first and foremost demonstrated by property law. Indeed, according to article 516 of the Code civil, which states that " property is either movable or immovable ", one has to admit that immaterial assets cannot validly be linked to movable or immovable property. Immaterial assets are opposed to material assets (property of nature, commodities, intellectual property of the public domain or without protection under intellectual property law). They refer to property that has an object and a corpus. Two types of immaterial assets have been identified: financial immaterial assets, bringing together currencies, units and shares in a company, financial instruments, liabilities and industrial immaterial assets, bringing together business and intellectual property.This is also demonstrated by conventional real-property surety law. The surety law reform project which was awarded to the Grimaldi Commission was the source of significant hope. It had only been rarely amended since the inception of the Code civil and the structure was weakening and needed updating. This weakening had three main grounds : readability first, in particular since conventional real-property surety law on immaterial assets had developed outside of the Code civil, efficiency and capability of the contemplated systems regarding the preservation of the interests of the debtor and the creditor. Practice and doctrine had been denouncing such complexity for long and were calling for amendments. Unfortunately, order n°2006-346 of March 23rd 2006 reforming surety law didn't restore confidence. By creating the lien as the conventional real-property surety on immaterial movable assets without creating a consistent system, it has only emphasized the obvious concerns and critics.However, we are convinced that French law has the means that are essential to save this subject. Indeed, the new system of pledge, as amended by order n° 2006-346 of March 23rd 2006, now has a system that is suitable for industrial immaterial assets. As for the "fiducie-sûreté", established by Act n° 2007-211 of February 19th 2007, it has revealed that, through the experiences observed abroad, it is fully efficient when it deals with financial immaterial assets.