Knowledge management is needed by WWF Indonesia's organization to record tacit knowledge from the organization's personnel. The organization has tried to implement knowledge management, but until now it has not been going well. Knowledge sharing culture is identified as one of the causes behind the failure of knowledge management in organizations. This research was conducted to find out what cultural factors caused the failure of the knowledge sharing at WWF Indonesia. Cultural factors were identified from previous literature studies, so that a model was formed to test the validity and reliability of each factor. The validity test results show the model is valid and reliable with a value. In addition, 100 answers to the questionnaire were identified, 3 categories of culture that did not work well in the organization are the compensation system, open communication, and trust.