Axial X-ray radiations of four types of wire-arrays were diagnosed via 1-D streak camera system on JL-Ⅰ.Because of the influence of Rayleigh-Taylor instability,wire-arrays mostly had the behavior that X-ray rose up later near both cathode and anode than that of the middle,X-ray near anode rose up later than that of cathode and the intensity of X-ray close to anode seemed weaker than that of cathode.With the comparison of different types of wire-arrays,the optimized mass per unit length of a 20 mm diameter w...