Since 1987, the green asparagus has been promoted as a crop with a good return. It is consumed fresh in the domestic market and also being exported to overseas both fresh and frozen. The objective of the study is to investigate the cost and return of asparagus production and also to study the factors affecting income of the asparagus farmers by focusing on the area of Chom Bueng Districrt, Ratchaburi Province. In the first year, the cultivation of asparagus requires high investment due to the relative cost of seeds and the difficulty in fully harvesting. The total cost was25,682 Baht/rai which mostly consisted of the cost of labor and fertilizer. The average income is 19,094 Baht/rai. The net loss of the first yer was 6,588 Baht/rai. However, they will earn a net income in the amount of 5,364 Baht/rai if only the cash is considered. In the second and the third year, the total cost was 23,811 Baht/rai which mostly consisted of the cost of labor and fertilizer. The average income was 41,841 Baht/rai. The net income was 18,030 Baht/rai. If only cash cost was calculated, the net income was 30,163 Baht/rai. The study also revealed that fertilizer is the most important factor affecting the income. Its elasticity for the first year was 0.9033. A one percent increase in the application of fertilizer in asparagus production will increase in come by 0.9033 percent. In second and the third year, the respective elasticity was 0.5860. A one percent increase of fertilizer utilization, 0.5860 percent of the income will be increase. Therefore, it can be concluded that the farmers can increase their income by increase the quantity of the fertilizer used in the production.