Doctoral thesis “Bioresource transition towards sustainable bioeconomy”, author Lauma Žihare, scientific supervisor Professor Dagnija Blumberga, Dr.habil.sc.ing. consultant leading researcher Anna Kubule, Dr.sc.ing is carried out in Riga Technical University, Institute of Energy Systems and Environment. The aim of the Doctoral Thesis is to develop an integrative methodology for the assessment towards sustainable bioeconomy through bioresource transition assessments using top-down and bottom-up approaches, transdisciplinarity analysis, and underused biomass potential use. The main contribution of the Thesis ascends from an integrated multi-level approach, that takes into account technical, socio-economic, environmental and market aspects. In order to reach the aims of the Thesis, the fallowing tasks were set: 1) to assess bioeconomy understanding and create consolidated view on bioeconomy; 2) to assess disciplinarity approaches towards sustainable bioeconomy; 3) to identify bioeconomy affecting factors, their interlinkages and propose possible nexus assessments; 4) to identify factor characteristic indicators; 5) to create factor nexus benchmark; 6) to create methodology for bioeconomy efficiency measures; 7) to identify potential bioresources that are underused and asses their potential value towards effective resource transition proposing new or existing bioresource value chains and their priorities; 8) to provide innovation transfer with market and economic analysis framework to determine if innovative bio-based product or technology would have the potential of entering market successfully; 9) to validate bio-resource potential with experimental analysis. The research presents several novel approaches not previously used in bioeconomy. In this thesis three main levels of bioresource transition assessment have been presented with methodology and case studies to approbate those methodologies. The outcome obtained in this Thesis extends the existing knowledge in bioeconomy for multi-level approach with transdisciplinary analysis. The results are beneficial for national and local and sectoral level governmental authorities, stakeholders and scientists.