Abstract:Optimal environmental temperature for differentiation and development of stamen and pistil have been tested cultured in vitro flowers of Taihangia rupestris. The optimal temperatures for stamen development was quite different from that for pistil development. The most suitable temperature scope for stamen development was on the low verge of 1 ～ 6 ‘C. Temperature over 18 ℃ led to abortion of all stamens. The temperature scope appropriate for pistil development was near to 6～26 ℃. That below 3 ℃ brought about cessation of most pistil development at early stage. The course of stamen abortion induced by high temperature started from the primordium stage in the stamen development and once this occurred it became irreversible despite of lowering the temperature. It is concluded that the temperature for unisexual male flower, unisexual female flowers and bisexual flowers development should be contralled at 1～3 ℃, 6～26 ℃ and 6～12 ℃ respectively. The results of the present experiment may open up a new train of thoughts for studies on the control of sexual organ development and male sterility.