1.Clinical unstability 2.Confusion and delirium 3.Bed ridden 4.Psychotic problem We will randomly allocate patients by using computer program nQuery advice 6.0. After patients sign inform consent we will record baseline characteristics, assess baseline Numerical rating scale (NRS), emotional status (ThaiHADs), Quality of life status (FACT-G). All patients will do the 25 MCQs test within 30 minutes before intervention. Video group will watch video 10 minutes and conventional group will receive pain education from trained nurse in the same period. The knowledge includes cancer pain definition, cancer pain management, pain assessment and role of patients in cancer pain management. After finishing intervention patients will the same 25 MCQs test (30 minutes) and patients can ask questions to the trained nurse.