The book is a continuation of development of" Boundary value problems for nonlinear elliptic equations and systems" and "Linear and quasilinear equations of hyperbolic and mixed types ".A large portion of the work is devoted to boundary value problems for general elliptic complex equations of first,second and fourth order,initial-boundary value problems for nonlinear parabolic complex equations of first and second order.Moreover,some results about first and second order complex equations of mixed (elliptic-hyperbolic) type are investigated .Applications of nonlinear complex analysis to continuum mechanics are also introduced.