The study has three objectives: 1) to study the level of human resource development, work autonomy, work motivation, innovative behavior, and work efficiency of sales staff in a selected life insurance company 2) to study the influence of human resource development, work autonomy, and work motivation that affect the innovative behavior of sales staff in Thai Life Insurance Company, Nakhon Pathom branch, and 3) to study the influence of sales staff’s innovative behavior in Thai Life Insurance Company, Nakhon Pathom branch affecting work efficiency. The samples were 300 employees. The data were analyzed by using the frequency, percentage, mean, standard deviation, Pearson’s correlation, and multiple linear regression analysis. The finding revealed that most of the respondents were female, aged 21-30 years old, in the position of sales representative, 3-4 years’ experience, earning an average monthly income of 15,000-20,000 baht, with a bachelor’s degree, and having single status. As a result of data analysis, it was found that the opinion level of variables, which is human resource development, work autonomy, work motivation, innovative behavior, and work efficiency, has an average at the highest level. The results of hypothesis testing demonstrated that human resource development, work autonomy, and work motivation had a positive influence on an employee’s innovative behavior, and the employee’s innovative behavior had a positive influence on work efficiency with statistical significance at level 0.01.