Abstract:An effective genetic transformation mediated by Agrobacterium tumefaciens, which harbours a cointegrate plasmid pTiB6S3SE:: pMON200, has been developed in red pepper (Capsicum annuum L. ). The intermediate vecter pMON200 contains a NPT Ⅱ gene under the nos promoter, which confers a transformed cell resistance to kanamycin. The cotyledons of aseptic pepper seedlings (12 d) were excised and pre-cultured on the regeneration medium (RM :MS+ 3 mg/L BA). After 2 days of pre-culture the explants were infected with a suspension of A. tumefaciens (10 8 cell/mL) and then cocultivated on the same medium for 2 days. The cultures were transferred onto the selection regeneration medium (SRM: RM + 100 μg/ml Km+ 500 μg/ml Cx). The multiple shoot buds were formmed in 2–3 weeks. For the elongation of the shoots the buds were transferred onto the selection elongation medium (SEM:MS basal nutrients +B5 vitamins+75 μg/ ml Km+300 μg/ml Cx). The shoots (2–3 cm)were excised and rooted in selection root medium (MS+0.1 mg/L IAA+50μg/ml Km). Rooted shoots were then potted. Total DNA was extracted from the putative transformed and control young leaves for Southern blot analysis. After digestion, electrophoresis and transfer, the membrance was hybridized with the probe of 1 kb Bam HI fragment of pCaMVNeo? All of 8 regenerants tested were transgenic with single or several copies of NPT Ⅱ gene.