It is challenging to develop Landsat-5 TM (TM5) image-based retrieval models for estimating the suspended particulate matter concentration (CSPM) in water when missing coincident ground CSPM measurements. This study, with the Poyang Lake in China as a case study, proposed an approach for developing TM5-based CSPM retrieval models with the assistance of moderate resolution imaging spectroradiometer (MODIS) images. After validation with an independent dataset, a cubic CSPM retrieval model of 250 m MODIS red band was used to estimate the CSPM values at 100 sampling points from the MODIS images (MODIS-based CSPM) captured at three time periods. The MODIS-based CSPM values at the time period with the largest CSPM variation were combined with their coincident TM5 image reflectance for TM5-based model calibrations. The linear, quadratic, cubic, power and exponential models of MODIS-based CSPM against TM5 single bands and their combinations were calibrated, respectively. Four best-fitting TM5-based CSPM models were selected to retrieve the CSPM values at 100 sampling points from the TM5 images (TM5-based CSPM) at the other two time periods, and the coincident MODIS- and TM5-based CSPM values were compared to assess TM5-based model performances. Model calibration results showed that the cubic and exponential models of TM5 red band (band 3) and red subtracting mid-infrared band (band 5) obtained the best fitting for estimating CSPM from the TM5 image on 12 August 2005, and they explained 94–97% of the variation of MODIS-based CSPM values with an estimated standard error of 6.617–8.457 mg/l. Model validations indicated that the exponential model of TM5 red band got the best result for estimating CSPM from TM5 images when the MODIS-based CSPM values were assumed as ground truths (correlation coefficient between MODIS- and TM5-based CSPM values = 0.96, root mean square error = 4.60 mg/l). We concluded that the TM5-based CSPM retrieval models could be developed with the assistance of MODIS, and the approach proposed in this study will be helpful for other researchers who also want to retrieve CSPM from TM5 image archive but without coincident ground CSPM measurements.