This research aim to study investment behavior and to study customer behavior upon mutual fund investment for living though securities company for retirement in Bangkok. By collecting data, concept, theory and related document. Researcher stated 400 sampling of retirement mutual fund investors within Bangkok, use questionaire as a tools for collecting data in discriptive and quantitative analysis by frequency distributions, percentage, mean, standard deviation. Analyze data for statistical hypothesis Chi-Square (X2) and One-way ANOWA significant level 0.05