This paper examines the economic effects of investment in developing and introducing Almond Late Flowering Cultivars (ALFC) in a period of 52 years from 1968 to 2020, developed in Sahand Horticultural Research Station (SHRS), using the economic surplus model and field survey data. ALFC make almond supply curve move less to the left when there is a chilling case, thus affect the economic surplus of producers and consumers. Results showed that because of ALFC, economic surplus of producers and consumers had been increased about 0.4 and 0.6 million US Dollars, respectively that the share of consumers from benefits was 58 percent. The social net present value of ALFC regarding to the cost of research and extension was about 0.1 million US Dollars. It was identified that the internal rate of return in developing and introducing of ALFC had been about 11%. The findings expressed that if the research investment in ALFC could keep the position of almond supply curve unchanged unless the weather conditions, then the economic surplus of producers and consumers would decreased 3 and 4.2 million US Dollars less annually, respectively and internal rate of return in almond research would be 33 %. Comparing the results showed that the introduction of late flowering cultivars could reduce the loss only 4 % per hectare. The results illustrated that investment in R&E of almond could make supply curve shift less in chilling situation because of decrease in cultivation cost, but it is necessary to enhance almond yield too. The findings identify that the efficiency of current system of R&E for almond is low. So it is a necessity to find ways for make better the R&E performance in Iran.