The optical/electrochemical and crosslinking properties of polycarbazole LbL films is studied using EC-SPR spectroscopy. The in situ electrochemical crosslinking and doping/de-doping properties are monitored for several different layered film structures. P4VPCBZ and PCEMMA are used as precursor polyelectrolytes, PAA and PDADMAC as non-crosslinkable polyelectrolytes, which are effective barrier layers for electron transfer. The changes in reflectivity and charge during CV illustrates that quantitative control of electrochemical crosslinking and doping/de-doping can be achieved by varying the composition of the precursor and counter-polyelectrolyte layers. The method may provide new opportunities for basic studies of model conjugated polymer systems and for electrooptic device applications.