Abstract: According to testing standard of hydrogeh-induced crack (HIC), ItlC of domestic X70 pipeline steels and weld were studied, and the effect of inclusion on HIC was particularly paid more attention. The results showed that resistance to HIC is not lower than that of base metal. With the increas of inclusions, the sensitivity to HIC increases. Furthermore, the configuration and distribution of inclusions affects the properties of domestic pipeline steels.