We report a general strategy to conceptualize a new design for pH-programmable self-assembly of plasmonic gold nanoparticles (AuNPs) tethered by random copolymers of poly(styrene-co-acrylic acid) (P(St-co-AA)). It is based on using pH as an external stimulus to reversibly change the surface charge of polymer tethers and to control the delicate balance of interparticle attractive and repulsive interactions. By incorporating -COOH moieties locally within PSt hydrophobic segments, the change in ionization degree of –COOH moieties can dramatically disrupt the hydrophobic attraction within a close distance. pH acts as a key parameter to control the deportonation of –COOH moieties and “programs” the assembled nanostructures of plasmonic nanoparticles in a stepwise manner. At a higher solution pH where -COOH groups of polymer tethers became highly deprotonated, the electrostatic repulsion dominated the self-assembly and it favored the formation of the end-to-end, anisotropic assemblies, e.g. 1-D single-line chains. At a lower pH, the less deprotonated -COOH groups led to the decrease of electrostatic repulsion and the side-to-side aggregates, e.g. clusters and multi-line chains of AuNPs, became favorable. The pH-programmable self-assembly allowed us to engineer a “manual” program for a sequential self-assembly by changing pH of the solution. We demonstrated that the two-step pH-programmable assembly could generate more sophisticated “multi-block” chains using two different sized AuNPs. Our strategy offers a general means for the programmable design of plasmonic nanoparticles into the specific pre-ordained nanostructures that is potentially useful for the precise control over their plasmon coupling.