The visual system processes light images by projecting various representations of the visual world to segregated regions in the brain through parallel channels. Retinal bipolar cells constitute the first parallel channels that carry different light response attributes to different parts of the inner plexiform layer (IPL). Here we present a systematic study on detailed axonal morphology and light response characteristics of over 200 bipolar cells in dark-adapted salamander retinal slices by the whole-cell voltage clamp and Lucifer yellow fluorescent (with a confocal microscope) techniques. Four major groups of bipolar cells were identified according to the patterns of axon terminal ramification in the IPL: 36% were narrowly monostratified (whose axon terminals ramified in one of the ten strata of the IPL), 27% were broadly monostratified, 19% were multistratified, and 18% bear pyramidally-branching axons. By analyzing the bipolar cells with narrowly monostratified axon terminals in each of the ten strata of the IPL, we found that several key light response attributes are highly correlated with the strata in which the cells _i^- axon terminals ramify. The ten IPL strata appear to be the basic building blocks for attributes of light-evoked signal outputs in all bipolar cells, and several general stratum-by-stratum rules were identified by analyzing the broadly monostratified, multistratified, and pyramidally-branching cells. These rules not only uncover mechanisms by which third-order retinal cells integrate and compute bipolar cell signals, but also shed considerable light on how bipolar cells in other vertebrates process visual information and how physiological signals may shape the morphology and projection of output synapses of visual neurons during development.