A sample including 22 BL Lac objects was collected. The possible correlations between the γ-ray emission at 1 GeV and the radio emission at 8.4GHz or 5.0GHz were investigated. Main results are as follows: 1） for minimum γ-ray data, there is no correlation between γ-ray and radio flux density. For maximum and average data, there are good correlations between γ-ray and radio emissions, with the maximum correlation coefficient reaching 0.85, and the chance probability p-4; 2） there are weak correlations between γ-ray spectral index and the radio spectral index. Therefore, the γ-ray radiation was the SSC process.