- theory of the social structure of pollution victims
- theory of the unconscious
- theory of the world system
- theory of thin plates
- theory of thin shells
- Theory of Three Beauties in Poetry
- Theory of Three Represents
- theory of three waves
- theory of Ti Wei
- theory of tolerance limit
- theory of topological algebras
- theory of topological spaces
- theory of transformation
- theory of transport phenomena
- theory of transversals
- theory of trigonometric series
- theory of trust
- theory of truth
- theory of turbulence
- theory of types
- theory of unequal development
- theory of unification in psychology
- theory of uniform algebras
- theory of univalent function
- theory of univalent functions