Abstract: Disturbance strength modeling of scintillation-producing irregularity is one of the main tasks in ionospheric scintillation models. A strength model for ionospheic irregularity is constructed with GPS scintillation data from Haikou China with relating foreign models as reference. The validity of the model is also checked with extensive data. The residual of model shows unbiased distribution with mean of zero and standard deviation 0.44 for the test data of Haikou from 2003 to 2008. More test with data from Haikou and Guangzhou in 2013 also show an unbiased distribution almost with standard deviation of 0.42. On the contrary, a biased result is obtained for the models constructed in the references with a mean of 0.33 and standard deviation 0.99 when the same Haikou data set is used. The test results show the validity of the scintillation irregularity model established in the work.