Abstract: This continuous propagation model of uncertainty is a new two-error standard curve regression theory, which is based on "York's algorithm". A brief introduction of the basic idea of the theory, mathematical model, and computer program, which is in accordance with the model is discussed in this paper. The program can perform simple standard curve straight line, quadratic curve, cubic curve, exponential curve, logarithmic curve; Y-single-error and x, y two-error (containing relative and absolute error) regression for standard curves. Moreover, detection limit can be calculated in terms of regression curve when given the allowed maximum error. This program is complete in function, friendly in interface and convenient in use, and is one of necessary tool softwares in chemical testing laboratory.