Miniature rose plantlets in the flowering stage were photoautotrophically grown on MS (MURASHIGE and SKOOG 1962) medium and subsequently exposed to 0 (control), 25, 50 or 100 mM NaCl for 14 d. The Na+ in the leaf tissues of salt stressed plantlets was enriched, resulting in proline accumulation and the degradation of total chlorophyll. Pigment degradation, chlorophyll a fluorescence diminution and net photosynthetic rate (Pn) reduction in miniature rose plantlets exposed to 100 mM NaCl were maximized when compared to the control, especially Pn reduction (77.96 % of control), leading to growth reduction. In contrast, the proline content in the salt stressed plantlets was enriched, indicating salt stress. In plants cultivated in vitro, the flowering percentage and the number of flowers per plantlet declined significantly under both 50 and 100 mM NaCl salt stress. The flowering stage of miniature rose plantlets was susceptible to salt stress, the reproductive developmental process being suppressed, which may be an effective indicator for salt tolerance screening in rose genotypes.