The article considers the formation and development of intellectual capital, including in the context of its relationship with human and social capital. The concept of intellectual capital is generalized and identified, its structure is defined according to different author's representations. It is determined that at the micro level intellectual capital is formed directly by human capital, structural (organizational) capital and client (consumer) capital. It was found that intellectual capital is assessed according to the methods of international organizations, including individual, collective, corporate (organizational), local and territorial, national, regional, international and global levels. Elements of intellectual capital are identified on the basis of their possible contact with the external environment: intellectual property, management system, infrastructure, social relations, technical and technological subsystem. It is emphasized that the theoretical aspects of intellectual capital from different authorial positions are presented in the global network economy, taking into account the intensification of information technology and innovation. It is revealed that the modern innovation environment creates preconditions for the formation of intellectual capital. Scientific knowledge, competencies of employees, experience, intellectual property, information technology are implemented in intangible products and assets of the network economy. It was found that most researchers understand intellectual capital as a set of intellectual assets, which can include: market assets (intangible assets related to market transactions); intellectual property as an asset (copyright, patents, trademarks of goods and services, know-how, trade secrets); human assets (a set of collective knowledge of employees of the enterprise, their creative abilities, the presence of leadership qualities); infrastructure assets (technologies, methods and processes that make the work of the enterprise possible). The expediency of considering intellectual capital in relation to human and social capital is emphasized, as the importance of social capital is represented by its special form, namely - networks, social norms and trust.