Jamming eavesdroppers with artificial noise can protect the communication between legitimate users. In this paper, we investigate the jamming design for a massive multiple-input multiple-output (MIMO) transmitter in a Rician fading channel. A generic analytical result on the secrecy outage probability (SOP) is derived to determine a location range of eavesdroppers, where the SOP is reduced by uniformly jamming the eavesdroppers. Then, the optimization of power allocation between messages and artificial noise is investigated for different scenarios. To further decrease the SOP, we propose a directional jamming scheme that can generate jamming signal towards the suspicious area where eavesdroppers can be located. At last, the numerical results validate our conclusion.