This paper aims to conduct theoretical modeling of tensile properties of thermoplastic composites developed from novel unidirectional recycled carbon fiber tapes. Unidirectional recycled carbon fiber tape structure is an innovative, sustainable and cost-efficient prepreg structure designed to develop carbon fiber reinforced plastics with the highest resource efficiency. In order to do modeling, existing theoretical models of tensile properties of unidirectional composites were reviewed in the first part of this paper. Subsequently, reviewed theoretical models were further modified by considering the tensile properties of fibers, fiber length, fiber orientation, fiber volume content and short fiber content to predict the tensile properties of composites based on novel tape structure. The results of this study reveal that the proposed theoretical models are in good agreement with the experimental results.