Dominated by different controlling factors，the response of river-dominated deltaic morphology to its growth processes is short of systematic quantitative study. On the basis of fractal geometry and variable controlling，we utilized sedimentary forward numerical modeling at an architecture scale to extract morphological types and features of river-dominated deltaic main bodies and channel-mouth bar complex lobes（CMCLs）and verify the controlling effects of sediment supply rates，sediment compositions，and basin bathymetry on morphology. Also，we established a quantitative characterization model relating the values of morphological features to dominant controlling factors of growth processes. The results indicate that the morphology of deltaic main bodies and CMCLs can be characterized by included angles between main distributary channels at initial river mouths，joint distance，the number of channel-mouth bar complexes at a river mouth or a joint，and the number and proportion of main distributary channels. In the case of low sediment concentration，deltaic main bodies are transformed from branching deltas with inter-distributary bays to sand-bar deltas with distributary networks when the river discharge rises. With the increase in the sediment discharge and the decrease in the sediment grain size，deltaic main bodies turn into branching deltas with inter-distributary bays and have weakened convergence，and CMCLs are transformed from complex finger lobes with multiple channels to complex finger lobes with few channels. Deltaic main bodies tend to be oval CMCLs with main distributary channels when the basin bathymetry increase.