In Cambodia, a large portion of the population is associated with small business instead of paid Employees, which contributes a major share of the country's economy. Recently, small business priority has grown higher than conventional agriculture practice and service sector. This study tries to analyze the investment costs and returns of three small businesses (Recycling shop, Antique shop and Small Restaurant) in Cambodia. Standard financial tools and techniques were used to determine investment costs and returns of specific business over five-year period of time. The sensitivity analysis of investment return was conducted by using internal rate of return and net present value analysis;return of investment was used to determine annual return and payback time, five years benefits and costs ratio were analyzed to evaluate five-year performance of return of each business. The sensitivity analysis shows that, antique shop has a higher internal rate of return 30.784% than recycling shop 25.362% and small restaurant 26.496% and at 20% discount rate the net present value is bigger for antique shop. The annual return of investment shows an increasing trend for selective three businesses and exhibit profit gain after five-year period of time, however the longer payback period (2.6 years) of the antique shop consider comparatively risky business than recycling shop and small restaurant. Five years' net benefits and costs ratio are higher for small restaurant 1.1684, whereas antique shop and recycling shop are 1.1631 and 1.1604. The high increasing discount rate of antique shop is indicating higher benefit and cost ratio in the future. From the result of the financial analysis, it is suggested that, selective three businesses can perform well in terms of gain profit and profitability, so these could be effective business practice for the developing socioeconomic of Cambodia.