Designing sustainable materials with tunable mechanical properties, intrinsic degradability, and recy- clability from renewable biomass through a mild process has become vital in polymer science.Traditional phe- nolic resins are generally considered to be not degrad- able or recyclable. Here we report the design and synthesis of linear and network structured phenolic polymers using facile polycondensation between natural aldehyde-bearing phenolic compounds and polymer- captans. Linear phenolic products are amorphous with T between -9C and 12C. Cross-linked networks from vanillin and its di-aldehyde derivative exhibited excel- lent mechanical strength between 6-64 MPa.The con- necting dithioacetals are associatively adaptable strong bonds and susceptible to degradation in oxidative conditions to regenerate vanillinThese results highlight the potential of biobased sustainable phenolic polymers with recyclability and selective degradation, as a comple- ment to the traditional phenol-formaldehyde resins.