This is a cross-sectional, observational and correlational survey study.This study is aim to survey the the knowledge, attitudes, and decision making towards clinical trials in cancer patients in Taiwan (R.O.C.), which attempts to invite some cancer patients who have been experienced the treatment clinical trials' informed consent process. The research tool is a questionnaire which includes some scale: (1)Clinical trial Knowledge scale, (2) Attitude toward randomized clinical trials scale, (3) Shared Decision Making(SDM-Q-9),(4) Satisfaction with Decision (SWD-scale), and (5) Decision Regret scale(DRS). The investigators expect the research outcome can provide some instructions to improve patients' autonomy, satisfaction of the decision making and communication process between patients and Medical professors whenever cancer patients participating in clinical trials.

This study is been conduct in National Taiwan University Hospital , Taiwan. The main measurement tool is a self-report questionnaire, which is designed to answer some outcome measures for the following aspect:

1. To find out the knowledge, attitudes, shared decision making level, subjective norm, and behavior intentions towards clinical trials in cancer patients.
2. To find out the main influencing factors of behavior intentions towards participating in clinical trials

Inclusion Criteria:

1. Cancer patients who have been approved lung cancer or liver cancer.
2. Patients who have been experienced the Informed consent process about clinical trial, which duration is in 6 months before they enter this study.

Exclusion Criteria:

1. Patients who have conscious disorientation that can not answer questionnaire
2. Patients only participate in some Gene clinical trials without treatment or drugs.

Adult, cancer patients who have experience in contact with clinical trials