Generalised spatial modulation (GSM) is a recently proposed transmission technology for Multiple-Input Multiple-Output (MIMO) wireless system, which extends the concept of spatial modulation (SM) and increases the spectral efficiency of SM. In this paper, a novel adaptive joint mapping scheme for GSM is presented. In adaptive joint mapping generalised spatial modulation (AJM-GSM) system, the input information bits are jointly mapped to a mapping table which indicates both the spatial constellation and the signal constellation. The mapping table is updated adaptively according to the channel state information, so the symbol error ratio (SER) performance of AJM-GSM is superior to GSM and SM. Monte Carlo simulations are carried out to validate the performance of AJM-GSM.