The existence of Java culture in Kemlagi, Mojokerto is still kept away. Malam Jum’at legi is one of tradition or ritual that still exist. Interestingly, this tradition becomes one of worship rituals of NU’s community believe. In this study, the researcher tried to find out how does NU’s community interpret about Malam Jum’at legi  as a tradition that changed become one of worship rituals. In addition, the researcher also tried to discover how does the way of this ritual implemented included the configuration of this ritual, the essential value of this worship ritual and the process of social interaction, which aim of this ritual will be directed. This ritual probably leads to associative or dissociative for human society. This study used culture acculturation theorists to know how does Malam Jum’at legi  ritual is finally changing and marge become Islamic Java culture. So, this study uses symbolic interaction theorists George Herbert Mead and Herbert Blummer. This theory is about the concept of “Self” is“I”, “Me”which shows the interaction symbols that have been implemented by the NU Kemlagi community in doing the worship activities. In addition, to give stronger evidence the meaning of this analysis, it also used Alfred Schutz’s phenomenology as an approach to know the meaning of NU’s Kemlagi in doing Malam Jum’at legi  through the motive and the subject in doing this ritual. The method that can be used for this study is a qualitative descriptive method of describing the social phenomena which are NU’s Kemlagi community activity in Malam Jum’at legi . To know the meaning of Malam Jum’at legi  ritual which is NU’s Kemlagi activity can be used phenomenology approach. The result of this study explains that Malam Jum’at legi  ritual have its own meaning for every NU’s community, straight faction and strange faction. This meaning can be based on the purposes and the objectives of them in doing malam Jum’at legi ritual such as wasilah, tahlilan, yasinan ziarah kubur, sholawatan, khatmil Qur’an, sema’an Qur’an dan shodaqohan. Based on NU straight faction, they can be called as the pure NU faction. They behave to be an associative, they agreed and very supportive in implementing this ritual because they assume that Malam Jum’at legi  is sacred night, mystics, hieratic, a moment to find blessings and to send the rewards for their dead family. Based on NU strange faction, they almost dissociative, ignorant and do not care, without following the ritual or the tradition. Therefore, they assume that Malam Jum’at legi  just a night, no meaning of that night. A night that has no idiosyncrasy and no blessing. Keywords              : Malam Jumat Legi, Ritual, Nahdlatul Ulama,