The laser spike of Ne_like argon at 469nm pumped by capillary discharge is mea sured with x_ray diode. Changing the pressure of Ar gas filled in the ceramic ca pillary and the peak value of the main discharge current, we study the effects o f experimental parameters on lasing time, which is the time of spike after the o nset of the main discharge current. The experimental results show that the soft x_ray laser is produced at the rise_time of the main discharge current which is 65%—75% of the peak at the lasing time. The lasing time can be delayed several ns when the pressure increases from 28Pa to 55Pa or the peak of main discharge c urrent decreases. In addition, there is maximum amplitude of the laser spike abo ut 42Pa.