This paper presents a study about the in vitro” multiplication of Stevia rebaudiana (Bert.) species and some conclusions about the influence of growing regulators’ concentrations in mixture for some biometrics characteristics of the vitro-plants, conclusions that were drawn up using a central-compound routable programme of second degree (CCRP2). There were established optimum concentrations for the two growing regulators in the mixture that is added to Murashige and Skoog medium (1962) for obtaining the best results of the biometrics characteristics. Thus a CCRP2 could be successfully used in botany.
