Physical layer security (PLS) is an effective means to protect communications against eavesdropping attacks by e xpl oiting physical characteristics of wireless channels. As the information and com munication technology (ICT) has been developed for decades, PLS attracts mo re and more attention of researchers. Here, PLS performance of the join t multi user s cheduling and the cooperative jammer sele c tion is explored. With the combination of the two techniques, the wireless c ommu nica tion security is investigated. In a wireless communication system wit h multiple users, multi user scheduling schemes are adopted to choose one legi t imate user of the best channel to transmit signals. Meanwhile, the eav esdroppers are interfered to keep the transmissions between BS and legi timate users confidential for avoiding the interference to the legitimate u sers. CJ signal is designed so that nulls are formed at the legitimate users . Simulatio n results show that the joint multi user scheduling and cooperative j a mmer scheme has a better performance of security than the multi user scheduling sch eme.