Seed germination test done in laboratory does not coincide with field emergence in general. The experiments were carried out to examine the effect of priming and $GA_3$, treatment to seeds of Platycodon grandiflorum; Codonopsis lanceolata and C. pilosula on lapsed time to first seedling emergence, seedling emergence, morphological characters and growth and the cause of poor emergence of C. pilosula. No-treatment as Control (water), priming or $GA_3$ treatment was done with only distilled water for 2 days, $CA(NO_3)_2$ 150 mM for 2 days or $GA_3$ 0.1 mM for 3 days, respectively. Seedling emergence rate was counted every 2 days but morphological characters and dry weight of shoot and root were measured on 38 days after sowing. Their internal seed structures were examined with Scanning Electron Microscope. C. pilosula had poorer seedling emergence rate than P grandiflorum and C. lanceolata showing nearly same rate: Compared to the other treatment (s) P. grandiflorum displayed higher rate in priming and $GA_3$, treatments but C. lanceolata or C. pilosula did the greatest rate in only $GA_3$ or priming treatment, respectively. $GA_3$ treatment to seeds of P. grandiflorum and C. lanceolata shortened the lapsed time to seedling emergence in comparison with Control, 2-days water imbibition before sowing. In all the species plant height and number of leaves per seedling became shorter and less in priming treatment than the other treatments except plant height of C. Pilosula while their hypocotyl length was nearly same in all treatments. Although priming treatment had nearly similar effect to morphological characters, $GA_3$ treatment forced greater shoot, root and aftermath total dry weight per seedling. Poor seedling emergence of C. pilosula was caused by its seed defect like cleavage or lack of embryo, poor development of embryo and endosperm or their separation.