What is polynomial regression A polynomial is a mathematical expression that is the sum of more than one monomial (Wikipedia). A monomial can be a constant or a variable (also called indeterminate). In a monomial, coefficients should only be involved with the operations of addition, subtraction, multiplication, and non-negative integer exponents (Wikipedia). For example, X2+5X-7 is a polynomial and is quadratic. Polynomial regression is the regression technique that tries to identify the polynomial that fits the relationship between a dependent variable (Y) and one or more independent variables (X1, X2...). When there is only one independent variable, it is called a univariate polynomial (Wikipedia). When there are multiple independent variables, it is called a multivariate polynomial (Wikipedia). Polynomial regression is widely used in biology, psychology, technology and management field (Jia, 2011). The Relationship Between Polynomial Regression and Other RegressionsHow do you use a polynomial regression? If we want to understand polynomial regression, we must first know what the relationship is between polynomial regression and other regressions. A simple linear regression studies the relationship between an independent variable and a dependent variable. In a simple regression model, we assume that there is only one independent variable that contributes to changes in the dependent variable and that the relationship between them is linear. However, this is usually an idealized case. In real-world practice, a dependent variable can be influenced by many factors. For example, wool yield is controlled by the weight, chest circumference and body length of sheep (Jia, 2011). This is the t...... middle of the paper ...... with the increase of indeterminates (Jia, 2011). And in the meantime the calculations also become very difficult. Now we can use linear regression techniques to solve the problem. After the transformation, the least squares method will be used to predict the unknown betas. The central concept of the least squares method is to make the sum of (y-ye)2 the minimum (Jia, 2011). You don't need to calculate them yourself because the process is complex. We usually use computer to get the results of least squares method. An example of using polynomial regression in SPSS（uses online data, shows SPSS steps, interpretations of results）Reference Jia, J. (2011). Statistics. Beijing, China: China Remin University Press.http://en.wikipedia.org/wiki/Polynomialhttp://en.wikipedia.org/wiki/Polynomial_regression