Abstract: Based on years of scientific research and in situ “prototype measurement” of geological disasters, author proposed six factors and their variations with time for risk identification or early recognition of geological disasters. The factors include: topographic forms (a), components and structures (b), initial states (c), induced factors (d), environmental conditions (e) and harmful objects (f) with its time (t). This method can be termed as “risk identification by six factors”, representing as R=f（a，b，c，d，e，f；t）. The variations of six factors determine the probability of encounters between geological hazards and human beings. To prove that, geological disasters induced by changing of typical factors over time were discussed. Compared with assessments over-focused on occurred hazard events, this dynamic thinking can provide a better understanding on time-dependent risk assessments and risk managements for disasters reduction.