Objective To analyze the clinicopathological characteris tics of systemic lupus erythematosus (SLE) with secondary antiphospholid syndrome (APS) . Methods Data of 11 cases of SLE with secondary APS (SLE with APS) admitted to Peking Union Medical College Hospital from January 2000 to March 2010 were retrospectively analyzed. Kidney biopsy was performed on all of these patients. Differences of clinicopathology and outcomes between SLE with and without APS were compared. Results Renal involvement was found in all the SLE with APS patients. The prominent clinical manifestations included hypertension (54.5%), nephrotic level of proteinuria (24 h proteinuria ≥3.5 g)(72.7%) and renal insufficiency (45.5%). Diastolic blood pressure, mean arterial pressure and glomerular filtration rate in SLE with APS were significantly higher than those in SLE without APS (all P＜0.05). In 8 out of 11 cases (72.7%), APS nephropathy (APSN) in kidney biopsy was found, characterized by small vessel vaso-occlusive lesions. These included thrombotic microangiopathy (TMA), fibrous intimal hyperplasia (FIH), focal cortical atrophy (FCA) and tubular thyroidization. Among those, 5 cases (45.5%) had chronic APSN and 4 (36.4%) had acute APSN (one case had acute and chronic APSN at the same time). The incidences of APSN and acute APSN in the SLE with APS group were significantly higher than those in SLE without APS group (P＜0.05). Conclusions The major renal manifestations of SLE with APS are hypertension, nephrotic level of proteinuria and renal insufficiency. Other than lupus nephritis, also a high incidence of APSN is found in SLE with APS patients.