To make clear of the type and origin of the secondary pores in P2x of Junggar Basin, the comprehensive analysis of the slice of the cast body, core, energy spectrum of canning electron microscope, heavy mineral, for- mation tested data etc is engaged. The secondary pores in P2x detrital reservoir are mainly resulted from the hydrol- ization of the volcanic clastic materials in alkalinity diagenetic environment and associated with analcite and albite, that are the residual pores after the metasomatism of them with the pyroclast; The distribution of the zeolite-type minerals is mainly controlled by the type of parent rocks and sedimentary facies belts in source region. And moreo- ver the laumontite is commonly associated with heulandite and generally developed in neutral-basic source region, while the analcite and albite are mainly developed in neutral-acidic source region; the heulandite is mainly devel- oped in the above-water sedimentary facies belts, on the contrary, the analcite and albite are mainly developed in the underwater ones; the development of the clastic reservoir pores cemented by the heulandite and laumontite is relatively poorer, the favorable reservoirs is mainly developed in the underwater fan-delta-front facies belts of the neutral-acidic source region in the are from Kelamayi to Baikouquan.