Abstract: In order to study the probability of high gain soft Xray laser in 3p3s transition of electron collisional excitation in neonlike ions of argon , a simulation of gas puff column with initial density 6.632×10－3g/cm3 irradiating by 1.5ps double pulses with a 1.2ns separation is presented. The results show that a wide region in which the abundance of the neonlike ion is more than 50% and the free electron density is more than 1020cm－3 is obtained. The short main pulse rapidly heats electrons to a temperature of higher than 1keV, and a high gain region is produced by collision of high density free electrons with Nelike argon ions .The gain region occurs about at a time scale of duration of pumping laser pulse, and its width is more than 100μm. The gain coefficient is 200~300cm－1.