A ZSM-5/MOR co-crystalline zeolite was synthesized without using the template. The physico-chemical proper-ties of the zeolite were characterized by XRD, FT-IR, SEM and TPD and then compared with the co-crystalline zeolite synthesized with a template. Analytical results indicated that they were similar in structure and composition. The influences ofpH value and Si/AI ratio on synthesis were studied. It was found that a high pH value or a low Si/A1 ratio could provide better environment for mordenite (MOR) crystallization. The zeolites applied as catalysts in naphtha catalytic cracking for producing ethylene and propylene showed outstanding catalytic performance with the total yield of ethylene and propylene reaching 55 m%. The process could achieve most favorable efficiency when the catalyst contained 5 m% of MOR.